Base station, terminal, random access preamble detection method and random access channel configuration method

ABSTRACT

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services.Disclosed are a base station and a random access preamble sequence detection method thereof, and a terminal and a random access channel configuration method thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 17/350,012,filed Jun. 17, 2021, which is a continuation of application Ser. No.16/611,105, now U.S. Pat. No. 11,051,262, filed Nov. 5, 2019, which isthe 371 National Stage of International Application No.PCT/KR2018/005219, filed May 4, 2018, which claims priority to ChinesePatent Application No. 201710313203.X, filed May 5, 2017, Chinese PatentApplication No. 201710682050.6, filed Aug. 10, 2017, Chinese PatentApplication No. 201710730237.9, filed Aug. 23, 2017, Chinese PatentApplication No. 201711138408.5, filed Nov. 16, 2017, and Chinese PatentApplication No. 201810027605.8, filed Jan. 11, 2018, the disclosures ofwhich are herein incorporated by reference in their entirety.

BACKGROUND 1. Field

The present disclosure relates to a configuration manner of a randomaccess channel in a field of wireless communication technique,particularly to a base station and a random access preamble sequencedetection method thereof, and a terminal and a random access channelconfiguration method thereof.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System’. The 5G communication system is considered to beimplemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, soas to accomplish higher data rates. To decrease propagation loss of theradio waves and increase the transmission distance, the beamforming,massive multiple-input multiple-output (MIMO), Full Dimensional MIMO(FD-MIMO), array antenna, an analog beam forming, large scale antennatechniques are discussed in 5G communication systems. In addition, in 5Gcommunication systems, development for system network improvement isunder way based on advanced small cells, cloud Radio Access Networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul, moving network, cooperative communication,Coordinated Multi-Points (CoMP), reception-end interference cancellationand the like. In the 5G system, Hybrid FSK and QAM Modulation (FQAM) andsliding window superposition coding (SWSC) as an advanced codingmodulation (ACM), and filter bank multi carrier (FBMC), non-orthogonalmultiple access (NOMA), and sparse code multiple access (SCMA) as anadvanced access technology have been developed.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the Internetof Things (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The Internet ofEverything (IoE), which is a combination of the IoT technology and theBig Data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology”“wired/wireless communication and network infrastructure” “serviceinterface technology”, and “Security technology” have been demanded forIoT implementation, a sensor network, a Machine-to-Machine (M2M)communication, Machine Type Communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing Information Technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, Machine Type Communication (MTC), andMachine-to-Machine (M2M) communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud RadioAccess Network (RAN) as the above-described Big Data processingtechnology may also be considered to be as an example of convergencebetween the 5G technology and the IoT technology.

With a rapid development of information industry, especially increasingdemands from a Mobile Internet and an Internet of Things (IoT), itbrings unprecedented challenges to future mobile communicationtechnologies. According to a report ITU-R M. [IMT.BEYOND 2020.TRAFFIC]from the International Telecommunication Union (ITU), it could beexpected that a growth of mobile traffic will increase nearly 1000 timesthat of 2010 (4G era) by 2020, and a number of user equipmentconnections would be more than 17 billion. With massive IoT devicesgradually penetrate the mobile communication network, the number ofconnected devices will be even more amazing. In response to thisunprecedented challenge, a communications industry and an academia haveembarked on a wide research for the fifth generation mobilecommunications technology (5G) to face the 2020s. Currently, a frameworkand an overall goal of the future 5G has been discussed in the ITU'sreport ITU-R M. [IMT.VISION], wherein a demand outlook, applicationscenarios and key performance indicators of the 5G were described indetail. For the new requirements in 5G, the ITU's Report ITU-R M.[IMT.FUTURE TECHNOLOGY TRENDS] provides information on technology trendsfor the 5G to address issues such as significant improvements in systemthroughput, user experience consistency, scalability, etc., in order tosupport IoT, latency, energy efficiency, cost, network flexibility,emerging services and flexible spectrum utilization and the like.

A random access process is an important way for a terminal in a systemto establish a connection with a base station. In LTE, a preamblesequence needs to be transmitted in a Physical Random Access Channel(PRACH) regardless of whether it is a contention-based random accessprocedure. The PRACH is configured and indicated through PRACHconfiguration information. Specifically, the PRACH configuration isdefined by means of a look-up table, including contents such as apreamble sequence format corresponding to the PRACH, availablesubframes, time domain density and frequency domain mapping information,etc.

In LTE, the contents in the PRACH configuration information aredifferent for different frame structures (a FDD frequency divisionduplexing or a TDD time division duplexing). For the FDD, the PRACHconfiguration includes the preamble sequence format and availablesubframe indices; for TDD, the PRACH configuration includes the preamblesequence format, a time domain PRACH density, and a version index.Meanwhile, for the TDD frame structure, a protocol defines each PRACHconfiguration index and a PRACH time domain-frequency domain resourcemapping manner corresponding to an uplink/downlink configuration. ThePRACH configuration modes in the LTE are given in the form of a look-uptable. The terminal reads the PRACH configuration information from aMaster Information Block (MIB) in a physical broadcast channel or aSystem Information Block (SIB) indicated by the MIB to obtain a PRACHtime-frequency resource.

SUMMARY

A PRACH structure in the LTE is relatively simple, and the terminal canknow the position of the time-frequency resource of the PRACH directlythrough the PRACH configuration information. In a 5G high-band systems,a multi-beam operation is required to compensate for a large path lossin the high-band channel by a beamforming gain. For the random accessprocedure under the multi-beam operation, a corresponding PRACHconfiguration (that is, the random access channel configuration) isneeded to be determined for each beam. If the PRACH configurationinformation mode in the LTE is still adopted, a signaling overheadrequired would be significantly increased, which will reduce anoperating efficiency of the system. Therefore, for the PRACHconfiguration mode in a 5G system (that is, a random access channelconfiguration corresponding to the PRACH configuration mode in the LTE),there is needed a new mode to improve the system operation efficiency.

In 5G, a problem solved by the present invention is heavy signalingoverheads caused by a random access channel configuration manner beingsimilar to a PRACH configuration in LTE, which would be not helpful toimprove efficiency of a system. For a multi-beam operation system beingpossible in 5G, it is needed to optimize the random access channelconfiguration manner similar to the PRACH configuration in LTD andconfiguration contents, but no documents or solutions are disclosed tosettle such problem currently.

According to an aspect of the present disclosure, there is provided arandom access channel configuration method comprising steps of:determining, by a terminal, optimal synchronization signal blocksaccording to a downlink measurement result; acquiring, by the terminal,an index of the random access channel configuration and information on apreamble sequence resource pool based on the optimal synchronizationsignal blocks; determining, by the terminal, a time-frequency resourceof corresponding random access occasion according to an associationbetween the synchronization signal blocks and the random access channelresources and/or the acquired random access channel configuration index;selecting, by the terminal, preamble sequences from the preamblesequence resource pool; and transmitting the selected preamble sequencesat the determined time-frequency resource for the random accessoccasion, wherein the index of the random access channel configurationincludes an index of a physical random access channel configuration, andthe index of the physical random access channel configuration comprises:a random access preamble format, a time-frequency information of therandom access channel, a number of the random access occasions includedin the random access channel and a number of the random access occasionsincluded in the random access channel in a time domain, or the index ofthe physical random access channel configuration further comprises atleast one of a number of the synchronization signal block associatedwith a same random access occasion, available time units of the randomaccess occasion, a number of the random access channels within a unittime unit in the time domain, a number of the random access occasionsincluded in the random access channel in a frequency domain.

In an example, the association between the synchronization signal blocksand the random access channel resources comprises a one-to-one mappingrelationship existed between the synchronization signal blocks and therandom access occasions, wherein a random access channel configurationinformation is carried on a Master Information Block (MIB) on abroadcast signal in the synchronization signal block or on a systeminformation block indicated by the MIB, and the random access channelconfiguration information indicated by the different synchronizationsignal blocks is same.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: when the randomaccess occasions in the random access channel are arranged continuouslyin both of the time domain and the frequency domain, and the associationare made in a time domain first criterion, numbers of the random accessoccasions in the random access channel in the time domain and thefrequency domain determined by the terminal based on the random accesschannel configuration information are M_(RO) and N_(RO) respectively,the number of the random access occasions in the random access channelis M_(RO)N_(RO), the number of the synchronization signal blocks isN_(SS)=M_(RO)N_(RO), and the index of the synchronization signal blockselected by the terminal based on the measurement result is n_(SS), anindex range is 0˜N_(SS)−1, then an index of the random access occasionin the time domain selected by the terminal is:

m _(RO)=mod(n _(SS) ,M _(RO)),

and an index of the random access occasion in the frequency domainselected by the terminal is:

n _(RO) =└n _(ss) M _(RO)┘,

wherein the operation mod(⋅) denotes a Modulo operation, and theoperation └⋅┘ denotes a Floor operation.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: the terminaldetermines a preamble sequence format according to the random accesschannel configuration, and obtains a number of time units, t_(msg1),occupied by the entire preamble sequences and a bandwidth of the randomaccess occasion, w_(msg1), expressed by a number of physical resourceblocks, wherein a start position of the random access occasion in thetime domain is (t+t_(msg1)m_(RO))th time unit, wherein parameter t is aposition information of the time-frequency resource carried by therandom access channel configuration; wherein a start position of therandom access occasion in the frequency domain is (n+w_(msg1)n_(RO))thphysical resource block, wherein parameter n is a position informationof the time-frequency resource carried by the random access channelconfiguration.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: when the respectiverandom access occasions in the random access channel are arranged at anequal interval and mapped and associated in the time domain firstcriterion, a start position of the random access occasion associatedwith the synchronization signal block n_(SS) in the time domain is the(1+(t_(msg1)+k)m_(RO))th time unit if the two random access occasionsadjacent to each other in the time domain are spaced by k time units;and a start position of the random access occasion associated with thesynchronization signal block n_(SS) in the frequency domain is the(n+(w_(msg1)+s)n_(RO))th time unit if the two random access occasionsadjacent to each other in the frequency domain are spaced by s physicalresource blocks.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: when the respectiverandom access occasions in the random access channel are arranged at anequal interval and mapped and associated in a frequency domain firstcriterion, if the index of the synchronization signal block selected bythe terminal according to the measure result is n_(SS) and the indexrange is 0˜N_(SS)−1 the index of the random access occasion in the timedomain selected by the terminal is:

m _(RO)=mod(n _(SS) ,N _(RO))

the index of the random access occasion in the frequency domain selectedby the terminal is:

n _(RO) =└n _(SS) /N _(RO)┘,

wherein N_(RO) is a number of the random access occasions in thefrequency domain.

Wherein the indices of the random access occasions arranged continuouslyin the random access channel satisfy the time domain first, or followthe frequency domain first criterion; alternatively, wherein the indicesof the random access occasions arranged at the equal interval in therandom access channel satisfy the time domain first, or follow thefrequency domain first criterion. Wherein the indices satisfying thetime domain first criterion are the indices of which the random accessoccasions are continuous in a same frequency domain resource; and theindices satisfying the frequency domain first criterion are the indicesof which the random access occasions are continuous in a same timedomain resource.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: the random accessoccasions are mapped on all of available uplink time units.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if one random accessoccasion occupies k_(m) time units, the one random access occasion isassociated to k_(m) associated adjacent uplink time units, but theuplink time units which are adjacent to the downlink time units and maynot be associated with other uplink time units are excluded withoutassociation.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if one random accessoccasion occupies the k_(m) time units, the one random access occasionis associated to the k_(m) associated adjacent uplink time units.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: the terminaldetermines a time and a frequency positions according to information onavailable time units of the random access occasions in the random accesschannels configuration information.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if the available timeunit exhausts while the mapping of the random access occasions has notcompleted yet, the mapping of the random access occasions is made withan adjacent frequency band and same available time units.

In an example, the random access occasions in the different time unitsuse different frequency resources.

In an example, the association between the synchronization signal blocksand the random access channel resources comprises a mapping relationshipbetween a plurality of synchronization signal blocks and one randomaccess occasion, wherein a random access channel configurationinformation is carried on a Master Information Block (MIB) on abroadcast signal in the synchronization signal block or on a systeminformation block indicated by the MIB, and the random access channelconfiguration information indicated by the different synchronizationsignal blocks is same.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if the number of thesynchronization signal blocks associated with a same random accessoccasion is S and the random access occasions are assigned in the timedomain first criterion, the index of the synchronization signal blockstarts from 0, and the number of available random access occasions inthe time domain is M_(RO), the time domain index of the random accessoccasion associated with the synchronization signal block n_(SS) iscalculated as:

m _(RO)=mod(└n _(SS) /S┘,M _(RO)),

and the frequency domain index of the random access occasion associatedwith the synchronization signal block n_(SS) is calculated as:

n _(RO) =└└n _(SS) /S┘/M _(RO)┘,

Wherein the terminal determines the time-frequency position of therandom access occasion according to method of any one described above,after it obtains the time domain index or frequency domain index of therandom access occasion in the random access channel.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if the number of thesynchronization signal blocks associated with a same random accessoccasion is S and the random access occasions are assigned in thefrequency domain first criterion, the index of the synchronizationsignal block starts from 0, and the number of available random accessoccasions in the frequency domain is N_(RO), the time domain index ofthe random access occasion associated with the synchronization signalblock n_(SS) is calculated as:

m _(RO)=mod(└n _(SS) /S┘,N _(RO)),

and the frequency domain index of the random access occasion associatedwith the synchronization signal block n_(SS) is calculated as:

n _(RO) =└└n _(SS) /S┘/N _(RO)┘,

Wherein the terminal determines the time-frequency position of therandom access occasion according to method described above, after itobtains the time domain index or frequency domain index of the randomaccess occasion in the random access channel.

In an example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: the terminal furtherdetermines the time-frequency position of the random access occasionaccording to the method described above, based on the number informationof the synchronization signal blocks associated with the same randomaccess occasion in the random access channel configuration information.

In an example, when the random access channel configuration informationcarried on the master information block on the broadcast signal in therespective synchronization signal blocks or carried on the systeminformation block indicated by the master information block is same, thesynchronization signal block carries a offset for the time-frequencyresource of the random access occasion associated with thesynchronization signal block with respect to a time-frequency positioninformation provided in the random access channel configuration, whereinwhen the random access channel configuration information carried on themaster information block on the broadcast signal in the respectivesynchronization signal blocks or carried on the system information blockindicated by the master information block is different, thetime-frequency resource information in the random access channelconfiguration directly represents the time-frequency resourceinformation of the random access occasion associated with thesynchronization signal block.

In the example, determining, by the terminal, a time-frequency resourceof corresponding random access occasion comprises: if the time-frequencyresource information provided in the random access channel configurationinformation is (t, n) while the offset information carried in thesynchronization signal block n_(SS) is t_(SS) and n_(SS) the time domainposition of the random access occasion associated with thesynchronization signal block n_(SS) is t+t_(SS) and the frequency domainposition is n+n_(SS).

According to another aspect of the present disclosure, there is provideda random access preamble sequence detection method of a base stationcomprising steps of: transmitting synchronization signal blocksincluding a primary synchronization signal, a secondary synchronizationsignal and a broadcast channel; detecting respective random accessoccasions in a random access channel; determining downlink transmittingbeams for transmitting a random access response according to timefrequency resources of the random access occasions and/or the detectedrandom access preamble sequences, if the transmission of the preamblesequences is detected; transmitting the random access response by usingthe determined downlink transmitting beams, wherein the detectedpreamble sequences are transmitted on the time frequency resources ofthe random access occasions determined by the terminal based on themethod described above.

According to a further aspect of the present disclosure, there isprovided an apparatus for acquiring and determining time frequencyresources of a random access channel in a terminal, and the apparatuscomprises: a downlink measurement module configured to determinesynchronization signal blocks based on a downlink measure result; aconfiguration information acquisition module configured to read randomaccess channel configuration information from the synchronization signalblocks; a random access occasion time frequency resource determinationmodule configured to determine a time frequency resource position of therandom access occasion according to the random access channelconfiguration and association information and so on; a preamble sequencetransmitting module configured to transmit the preamble sequence on therandom access occasion, wherein the random access occasion timefrequency resource determination module determines the time frequencyresource position of the random access occasion based on the methoddescribed above.

According to a still further aspect of the present disclosure, there isprovided a preamble sequence detection apparatus of a base station,which comprises: a synchronization signal block transmitting moduleconfigured to transmit the synchronization signal blocks; a preamblesequence detection module configured to detect the preamble sequences onthe respective random access occasions of the random access channel; adownlink beam determination module configured to determine downlinkbeams according to the time frequency resources of the random accessoccasions and the preamble sequences; a random access responsetransmitting module configured to transmit a random access responseusing the determined downlink beams, wherein the preamble sequencesdetected in the preamble sequence detection module are transmitted onthe time frequency resources of the random access occasion determinedbased on the method described above.

The present disclosure provides an acquisition and determination mannerof time-frequency resource of the random access channel in a multi-beamoperation system. With the methods provided by the present disclosure,the system can configure the time-frequency resources of the randomaccess occasions corresponding to the different beams in a smallersignaling overhead. Further, the terminal can acquire the information onthe random access occasion more quickly, so that the entire performanceand operation efficiency of the system are improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description given hereinafter and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present disclosure and wherein:

FIG. 1 is a flowchart illustrating a method for determining by aterminal time frequency resources of a random access channel accordingto the present disclosure;

FIG. 2 is an exemplary view illustrating an association betweensynchronization signal blocks and random access occasion according to afirst embodiment of the present disclosure, wherein a one-to-one mappingrelationship exists between the synchronization signal blocks and therandom access occasions;

FIG. 3 is an exemplary view illustrating a determination manner of therandom access occasion in the random access channel according to thefirst embodiment of the present disclosure;

FIG. 4 is an exemplary view illustrating a transmitting positiondetermination manner of the random access occasion in a frame structureof time division multiplexing according to the first embodiment of thepresent disclosure;

FIG. 5 is an exemplary view illustrating a transmitting positiondetermination manner of the random access occasion in another framestructure of time division multiplexing according to the firstembodiment of the present disclosure;

FIG. 6 is an exemplary view illustrating a transmitting positiondetermination manner of the random access occasion in a further framestructure of time division multiplexing according to the firstembodiment of the present disclosure;

FIG. 7 is an exemplary view illustrating a time index determinationmanner of the random access occasion according to the first embodimentof the present disclosure;

FIG. 8 is an exemplary view illustrating another time indexdetermination manner of the random access occasion according to thefirst embodiment of the present disclosure;

FIG. 9 is an exemplary view illustrating an association between aplurality of synchronization signal blocks and a same random accessoccasion according to a second embodiment of the present disclosure,wherein a mapping relationship exists between the plurality ofsynchronization signal blocks and one random access occasion;

FIG. 10 is an exemplary view illustrating a structure of a TDD frame;

FIG. 11 illustrates a first calculation method for a start timeaccording to the seventh embodiment of the present disclosure;

FIG. 12 illustrates a calculation method of the start time when a startsymbol index is not 0 according to the seventh embodiment of the presentdisclosure;

FIG. 13 illustrates a second calculation method for the start timeaccording to the seventh embodiment of the present disclosure;

FIG. 14 illustrates a second determination method for a start positionof a random access channel according to the seventh embodiment of thepresent disclosure;

FIG. 15 is an exemplary view illustrating a random access preamblesequence detection method at the base station side according to thepresent disclosure;

FIG. 16 illustrates a random access channel time frequency resourceacquisition and determination apparatus included in the terminalaccording to the present disclosure;

FIG. 17 illustrates a preamble sequence detection apparatus included inthe base station according to the present disclosure; and

FIG. 18 illustrates an index configuration matter for an uplink/downlinkconfiguration according to the present disclosure.

DETAILED DESCRIPTION

Thereafter, the present disclosure would be explained in connection withdrawings in details.

For the issue of random access channel configuration under themulti-beam operation in 5G, the present disclosure provides a randomaccess channel configuration manner. Particularly, by referring FIG. 1 ,FIG. 1 is a flowchart illustrating a method for determining timefrequency resources of a random access channel according to the presentdisclosure.

In FIG. 1 , at step S110, the terminal determines optimalsynchronization signal blocks according to a downlink measurementresult. At step 120, the terminal reads an index of the optimalsynchronization signal block, and reads an index of the random accesschannel configuration therein and information on a preamble sequenceresource pool from a Master Information Block (MIB) in a broadcastchannel therein or from a System Information Block (SIB) indicated bythe MIB. At step S130, the terminal determines a time-frequency resourceof corresponding random access channel according to an associationbetween the synchronization signal blocks and the random access channelresources, which is predefined or informed in the MIB or SIB, and theinformation on the read random access channel configuration index. Atstep S140, the terminal selects preamble sequences from the preamblesequence resource pool, and transmits the selected preamble sequences atthe random access channel time frequency resource determined in stepS140.

As compared with the prior art, the solution proposed by the presentdisclosure can notice the random access channel time frequency resourcewith less signaling, which saves the signaling overheads and improves anefficiency and a performance of the system indication.

First Embodiment

In the present embodiment, an indication manner of a physical randomaccess channel configuration information would be discussed inconnection with a detailed system. In the present embodiment, the systemoperates in a high frequency band, and copes with a notable path loss inthe high frequency band through a beam forming gain by utilizing amulti-beam operation and beam forming, etc. In order to synchronize aplurality of downlink beams, a synchronization channel of the system isconsisting of a plurality of synchronization signal blocks (SS blocks),each of the synchronization signal blocks includes a PrimarySynchronization Signal (PSS), a Secondary Synchronization Signal block(SSS) and a physical broadcast channel. The different synchronizationsignal blocks are transmitted by same or different downlink transmittingbeams. In the present embodiment, it is assumed that the differentsynchronization signal blocks are transmitted by the different downlinktransmitting beams.

To facilitate the base station to determine the preferred transmittingbeam, an association is established between the synchronization signalblocks and the physical random access channel. In the presentembodiment, it is assumed that the association is preset, that is tosay, the association is known commonly by both the base station and theterminal, and the terminal may determine the corresponding random accesschannel time frequency resources according to the physical random accesschannel configuration information and corresponding indicationinformation.

In the present embodiment, it is assumed that the random access channelis consist of a plurality of random access occasions, and one randomaccess occasion is configured to transmit a preamble sequence defined ina format of random access preamble sequence. Meanwhile, as theassociation between the synchronization signal blocks and the physicalrandom access channels, a mapping relationship is established betweenone synchronization signal block and one random access occasion, asillustrated in FIG. 2 . FIG. 2 is an exemplary view illustrating anassociation between synchronization signal blocks and random accessoccasions according to the first embodiment of the present disclosure,wherein a one-to-one mapping relationship exists between thesynchronization signal blocks and the random access occasions.

It should be noted that a case where an association is establishedbetween the plurality of synchronization signal blocks and one samerandom access occasion would be discussed later in connection with thesecond embodiment illustrated in FIG. 9 .

In the first embodiment, as same as illustrated in FIG. 1 , the terminaldetermines the optimal synchronization signal block according to thedownlink measurement result when it tries to access. The measurementresult comprises a Reference Signal Received Power (RSRP) of the PSSand/or a RSRP of the SSS. The terminal selects one or moresynchronization signal blocks with an optimal measurement result (forexample, with the maximum RSRP), and read information therein. Ifmultiple synchronization signal blocks are selected, the terminalselects the synchronization signal blocks whose measurement results isgreater than a certain preset threshold. When the information is readfrom the synchronization signal block, a preset rule is followed, forexample, the information in the synchronization signal block with themaximum RSRP is read, or the information in the multiple synchronizationsignal blocks is read at an equal probability. It should be noted thatreading of the information from the synchronization signal block refersto determination of an index of this synchronization signal block fromthe selected synchronization signal blocks, reading of a MasterInformation Block (MIB) in its broadcast channel and correspondingRemaining Minimum System Information (RMSI) indicated by the MIB. Itshould be understood that reading of the information from the multiplesynchronization signal blocks at the equal probability refers to selectone synchronization signal block from the multiple synchronizationsignal blocks with a value being greater than the preset threshold atthe equal probability and read the information therein.

The process and criterion for determining the synchronization signalblock described above and the manner for determining the random accesschannel configuration are also applicable to an random access retryprocess as the random access process fails. In particular, if the randomaccess process fails, the terminal determines the utilized timefrequency resources for the random access occasion according to thelatest measurement result of the downlink signal when it makes a powerclimbing and initiates a random access retry process. If the selectioncriterion of the downlink signal indicates to select the synchronizationsignal block with the maximum RSRP, the terminal still selects thesynchronization signal block with the maximum RSRP and selects therandom access occasion associated with it to perform the random accessretry process when the random access retry process is initiated. If theselection criterion of the downlink signal indicates to select onesynchronization signal block from the multiple synchronization signalblocks with the value being greater than the preset threshold at theequal probability, the terminal confirms whether the RSRP of thesynchronization signal block associated with the current random accessoccasion is still greater than the threshold when it initiates therandom access retry process at first, if yes, the terminal performs therandom access retry process using the time frequency resources of thecurrent random access occasion. If not, the terminal selects a pluralityof synchronization signal blocks with values being greater than thepreset threshold from the latest measurement result, selects onesynchronization signal block at the equal probability therefrom,determines the random access occasion according to the association, andinitiates the random access retry process.

The terminal read information from the above determined optimalsynchronization signal blocks. Particularly, the index of thesynchronization signal block is determined through the PSS, SSS and/orthe MIB in the broadcast channel; the random access channelconfiguration information is read from the MIB in the broadcast channel,or the SIB indicated by the MIB, and the random access preamble sequencepool information is read; and other information necessary for assessingis read.

The terminal determines the time-frequency resource of the random accesschannel according to the read random access channel configurationinformation and the preset association between the synchronizationsignal blocks and the random access channel resources. The terminalselects the preamble sequence from the preamble sequence resource pool,and transmits the selected preamble sequence on the determined timefrequency resource position of the random access channel.

In an example, when the terminal determines the time-frequency resourceof the random access channel according to the read random access channelconfiguration information and the preset association between thesynchronization signal blocks and the random access channel resources,one possible manner for determining the random access channel timefrequency resource is as follows.

At first, for the read random access channel configuration information,the random access channel configuration information comprises an indexof the physical random access channel configuration. The index of thephysical random access channel configuration indicates: a random accesspreamble sequence format, a time-frequency resource information of therandom access channel, a number of the random access channels in a unittime unit in the time domain, a number of the random access occasionsincluded in the random access channel and a number of the random accessoccasions included the random access channel in a time domain. The indexof the random access channel configuration is in a form of index table,both the base station and the terminal save the index table, and theterminal knows the random access channel configuration through the indexof the random access channel configuration. An example of the aboverandom access channel configuration may be given by Table 1.

The information of the random access channel configuration furthercomprises other information about the time frequency resource positionof the random access occasion.

TABLE 1 example of index table of random access channel configurationNumber Of Density of Number of Random Time Preamble Random Random AccessFrequency Sequence Access Access Occasions In Resource Index FormatChannel Occasions Time Domain Information 0 0 0.5 8 4 (t₀, n₀) 1 0 1 168 (t₁, n₁) 2 1 1 8 8 (t₂, n₂) 3 1 2 16 8 (t₃, n₃) . . . . . . . . . . .. . . . . . .

It should be noted that the time unit described previously may berepresented by an absolute time, for example, a number of the randomaccess channels within 1 ms; or may be represented by a radio frame, asubframe or a slot, for example, a number of the random access channelswithin the radio frame. The density of the random access channel inTable 1 indicates same contents as the number of the random accesschannels within the unit time unit. Wherein 0.5 indicates one randomaccess channel per two time units, 1 indicates one random access channelper time unit, and 2 indicates two random access channels per timeunits. The time frequency resource information shown in Table 1 is givenin a form of combination of the time index and the frequency index,wherein the time index may be represented by an index of the unit time,for example, a subframe index, a slot index or a symbol index; and thefrequency index may be represented by an index of a physical resourceblock.

In other representations for other configuration manners of the randomaccess channel configuration information, the time frequency resourcemay be divided and represented respectively, for example, the timefrequency resource information may be deleted from the Table andcontents about a time domain index and a frequency domain index may beadded, wherein the time domain index is represented by the index of theunit time, for example, the subframe index, the slot index or the symbolindex; and the frequency index may be represented by the index of thephysical resource block. In the way, the time domain index may also givea time index available in the unit time, for example, the subframe indexpossible existing for the random access channel in the radio frame, orthe slot index or symbol index possible existing for the random accesschannel in the subframe, or the symbol index possible existing for therandom access channel in the slot. In other configuration manner, thetime frequency position information may be indicated separately, insteadof being included in the index of the physical random access channelconfiguration.

In the above description for the configuration manner shown in Table 1,the number of the random access occasions and the number of the randomaccess occasions in the time domain are used to determine a distributionof the respective random access occasions in the random access channelin the time domain and the frequency domain. In the above example, thedistribution of the random access occasions in the random access channelin the time domain and the frequency domain may be deduced by acquiringthe number of the random access occasions in the random access channeland the number of the random access occasioning the time domain. That isto say, the number of the random access occasion in the frequency domainmay be obtained by dividing the number of the random access occasions bythe number of the random access occasions in the time domain.

In other configuration manners for the random access channelconfiguration information, the number of the random access occasions inthe time domain and the number of the random access occasions in thefrequency domain may be indicated, instead of the number of the randomaccess occasions and the number of the random access occasions in thetime domain; alternatively, the number of the random access occasionsand the number of the random access occasions in the frequency domainmay be indicated, then the terminal may obtain the number of the randomaccess occasions in the time domain via calculation.

It should be noted that the random access channel configurationinformation carried in the MIBs on the broadcast signals in therespective synchronization signal blocks or in the SIBs indicated by theMIBs are same. Wherein the time-frequency resource information is thetime-frequency resource of the first random access occasion in therandom access channel. The first random access occasion represents arandom access occasion with a minimum time index and a minimum frequencyindex.

Further, in the configuration in the Table 1, a density of the randomaccess channels or a number of the random access channels in a unit timeunit is used to denote a number of available random access channels inthe unit time unit in time domain. Similarly, several available randomaccess channels may also exist in frequency domain, and may be acquiredby adding corresponding parameter(s) in the random access channelconfiguration information.

The terminal may determine the time-frequency position of the randomaccess occasion corresponding to the selected synchronization signalblock according to the described-above association between thesynchronization signal blocks and the random access channels, which isimplemented by a predetermined criterion, after acquiring the randomaccess channel configuration information.

A possible association is, a one-to-one mapping relationship is existedbetween the synchronization signal blocks and the random accessoccasions (as illustrated in FIG. 2 ), that is, the differentsynchronization signal blocks are associated with the differenttime-frequency resources of the random access occasions. Thepredetermined criterion is a time domain first criterion or a frequencydomain first criterion, the random access occasions in the random accesschannel are numbered and indexed; the criterion further comprises aninterval among the adjacent random access occasions in the time domainand the frequency domain. Wherein, the time domain first criterionnumbers the time resources first and then the frequency resources asnumbering the resources, while the frequency domain first criterionnumbers the frequency resources first and then the time resources asnumbering the resources.

FIG. 3 is an exemplary view illustrating a determination manner of therandom access occasion in the random access channel according to thefirst embodiment of the present disclosure.

Particularly, below will describe a determination of, by the terminal,the time-frequency position of the random access occasion correspondingto the selected synchronization signal block.

Case 1

Assuming previously: the random access occasions in the random accesschannel are arranged continuously both in the time domain and thefrequency domain, and are mapped and associated in the time domain firstcriterion. This example is applicable to a Frequency DivisionMultiplexing (FDM) structure, namely a case where uplink framestructures are continuous.

The terminal receives the random access channel configurationinformation, and determines a time-frequency resource of the randomaccess channel (namely the time-frequency resource of the first randomaccess occasion in the random access channel) according to theinformation. The numbers of the random access occasions in the randomaccess channel in the time domain and the frequency domain determined bythe terminal based on the random access channel configurationinformation are M_(RO) and N_(RO) respectively, the number of the randomaccess occasions in the random access channel is M_(RO)N_(RO), thenumber of the synchronization signal blocks is N_(SS)=M_(RO)N_(RO) bytaking the one-to-one association between the synchronization signalblocks and the random access occasions into account.

An index of the synchronization signal block selected by the terminalbased on the measurement result is n_(SS), an index range is 0˜N_(SS)−1then an index of the random access occasion in the time domain selectedby the terminal is:

m _(RO)=mod(n _(SS) ,M _(RO)),

and an index of the random access occasion in the frequency domainselected by the terminal is:

n _(RO) =└n _(SS) /M _(RO)┘,

wherein the operation mod( ) denotes a Modulo operation, and theoperation └⋅┘ denotes a Floor operation. The above rule indicates that,if index of the synchronization signal block obtained by the terminalbased on the measurement result is n_(SS), the random access occasionassociated therewith is the random access occasion which is the m_(RO)thin the time domain and the n_(RO)th in the frequency domain. That is tosay, the time domain index of the random access occasion associated withthe synchronization signal block with the index of n_(SS) is m_(RO), andthe time domain index of the random access occasion associated with thesynchronization signal block with the index of n_(SS) is n_(RO).

The terminal determines a preamble sequence format according to therandom access channel configuration, and obtains a number of time units,t_(msg1), occupied by the entire preamble sequences and a bandwidth ofthe random access occasion, w_(msg1), expressed by a number of physicalresource blocks. After obtaining such information, the time-frequencyresource of the random access occasion may be calculated in connectionwith the indices of the random access occasion both in the time domainand the frequency domain. Particularly, a start position of the randomaccess occasion in the time domain is (t+t_(msg1)m_(RO))th time unit,wherein parameter t is a position information of the time-frequencyresource carried by the random access channel configuration; a startposition of the random access occasion in the frequency domain is(n+w_(msg1)n_(RO))th physical resource block, wherein parameter n is aposition information of the time-frequency resource carried by therandom access channel configuration.

Case 2

Assuming previously: the respective random access occasions in therandom access channel are distributed at an equal interval and mappedand associated in the time domain first criterion.

For example, a start position of the random access occasion associatedwith the synchronization signal block n_(SS) in the time domain is the(t+(t_(msg1)+k)m_(RO))th time unit if the two random access occasionsadjacent to each other in the time domain are spaced by k time units.

A start position of the random access occasion associated with thesynchronization signal block n_(SS) in the frequency domain is the(n+(w_(msg1)+s)n_(RO))th physical resource block if the two randomaccess occasions adjacent to each other in the frequency domain arespaced by s physical resource blocks.

It should be noted that the above description is also applicable to themanner of associating in the frequency domain first criterion. Inparticular, if the index of the synchronization signal block selected bythe terminal according to the measure result is n_(SS) and the indexrange is 0˜N_(SS)−1, the index of the random access occasion in the timedomain selected by the terminal is:

m _(RO)=mod(n _(SS) ,N _(RO)),

the index of the random access occasion in the frequency domain selectedby the terminal is:

n _(RO) =└n _(SS) /N _(RO)┘,

wherein N_(RO) is a number of the random access occasions in thefrequency domain.

The Case 1 described above is more applicable to determine thetime-frequency position of the random access occasion corresponding tothe synchronization signal block selected by the terminal in the FDMstructure (namely the case where the uplink frame structures arecontinuous).

As to determining the time-frequency position of the random accessoccasion corresponding to the synchronization signal block selected bythe terminal in a Division Multiplexing (TDM) structure (namely a casewhere the uplink frame structures are non-continuous), the above examplemay be modified. Below will explain by referring to FIGS. 4, 5 and 6 .

Regarding the TDM structure, the index m_(RO) in time domain and theindex n_(RO) in frequency domain of the random access occasionassociated with the index n_(SS) of the synchronization signal block maybe calculated following the above process. The terminal may take thepreamble sequence format information included in the random accessconfiguration, or a number of time units, k, occupied by the entirepreamble sequences and a bandwidth s expressed by the number of physicalresource blocks into account.

In order to determine the index in the time domain of the random accessoccasion in the TDM structure, an index of a start time unit amongavailable uplink time units may be calculated according to the aboveprocess and a transmitting time position of the random access occasionmay be determined according to current uplink/downlink configurations.

FIG. 4 is an exemplary view illustrating a transmitting positiondetermination manner of the random access occasion in a frame structureof TDM according to the first embodiment of the present disclosure.

In FIG. 4 , the frame structure of TDM consists of downlink subframes,uplink subframes and special subframes. Wherein the special subframesare used to conversion to a uplink transmission from a downlinktransmission. In the example shown in FIG. 4 , it is assumed that onerandom access channel occupies one subframe and is only associated toall of the available uplink subframes.

FIG. 5 is an exemplary view illustrating a transmitting positiondetermination manner of the random access occasion in another framestructure of TDM according to the first embodiment of the presentdisclosure; and FIG. 6 is an exemplary view illustrating a transmittingposition determination manner of the random access occasion in a furtherframe structure of time division multiplexing according to the firstembodiment of the present disclosure.

In the examples illustrated in FIGS. 5 and 6 , one random accessoccasion may occupy a plurality of time units.

Processing of FIG. 5 will be explained as follows. if one random accessoccasion occupies k_(m) time units, k_(m) adjacent uplink time units areassociated and mapped, and the uplink time units which are adjacent tothe downlink time units and may not be associated with other uplink timeunits are excluded without association.

In the example illustrated in FIG. 5 , one random access occasion needsto occupy two subframes. In all of the available uplink subframes, twosubframes adjacent in the time domain are associated and paired totransmit one random access occasion. A subframe 4 and a subframe 9 (theindex range is 0˜9) cannot be paired because their adjacent subframesare downlink subframes, thus they are not used to transmit the randomaccess occasion.

It should be noted that the time unit is the subframe both in theexamples illustrated in FIGS. 4 and 5 . The time unit may be a slot or asymbol in other possible implementations.

Processing of FIG. 6 will be explained as follows. if one random accessoccasion occupies k_(m) time units, k_(m) adjacent uplink time units areassociated and mapped. This processing is different from the onedescribed previously in that the present processing considers only theuplink time unit, regardless of the downlink time unit, which leads to ahigher utilization efficiency but may risk an interrupting of thepreamble sequence by the downlink time units.

In the example illustrated in FIG. 6 , each random access occasion needstwo subframes, therefore every two uplink subframes are used to transmitone random access occasion. In FIG. 6 , the second random accessoccasion is associated to two subframes separated in the time domain andtransmitted.

It should be noted that the time unit is the subframe in the exampleillustrated in FIG. 6 . The time unit may be a slot or a symbol in otherpossible implementations.

Above describes the determination manners of the time-frequencyresources of the random access occasions applicable to the FDM (FIG. 3 )and TDM (FIGS. 4, 5 and 6 ), respectively.

Another manner for determining the time index of the random accessoccasion is to add indices of the available time units of the randomaccess occasions in the random access channel to an index table of therandom access channel configuration. Such manner is also applicable tothe frame structure of both the FDM and the TDM.

FIG. 7 is an exemplary view illustrating a time index determinationmanner of the random access occasion according to the first embodimentof the present disclosure; and FIG. 8 is an exemplary view illustratinganother time index determination manner of the random access occasionaccording to the first embodiment of the present disclosure.

For example, the indices of the available time units of the randomaccess occasions are added in the random access channel configurationindex. One possible representation is shown in Table 2 below.

TABLE 2 example of index table of another random access channelconfiguration Available Density of Number of Time- Time Units PreambleRandom Random Frequency Of Random Sequence Access Access Resource AccessIndex Format Channel Occasions Information Occasion 0 0 0.5 8 (t₀, n₀)(1, 2, 3, 5) 1 0 1 16 (t₁, n₁) (1, 2, 3) 2 1 1 8 (t₂, n₂) (1, 3, 5) 3 12 16 (t₃, n₃) (1, 5) . . . . . . . . . . . . . . . . . .

In the Table 2, a parameter representing the available time unit of therandom access occasion is added, and the number of the available randomaccess occasions in the time domain may be acquired through theavailable time units of the random access occasions directly. In theTable 2, the available time unit is represented by an offset withrespect to the time unit of the first random access occasion in therandom access channel. For example, the available time units of therandom access occasions in the index 0 is (1, 2, 3, 5), which denotesthat the available time units of the random access occasions are the1st, 2nd, 3rd and 5th time units with respect to the first random accessoccasion in the random access channel, as illustrated in FIG. 7 .

In the above example, the first time unit is the time unit positionindicated in the random access channel configuration information. Theavailable time units of the random access occasions in the index tablemay be calculated from the first time unit, and the start number of theindices, namely the index of the first time unit, is 1. In otherpossible implementations, the index of the first time unit may startfrom 0.

In the method described above, the available time unit is a relativevalue, that is, the time unit index with respect to the first time unitof the random access channel. In other possible implementations, it alsomay be represented as a time unit absolute value, for example, the timeindex of the available random access occasion may be the index of apossible subframe, a possible slot or a possible symbol.

After receiving the random access channel configuration information, theterminal needs to determine a time position of the random accessoccasion after it calculates the time-frequency indices of the randomaccess occasions associated with the selected synchronization signalblocks. The terminal determines the time positions and frequencypositions of the random access occasions according to information onavailable time units of the random access occasions in the random accesschannels configuration information and the preset mapping rules.

A possible preset rule may be to map the random access occasions in thetime first criterion. If the available time units exhaust but themapping of the random access occasions has not completed, the mapping ofthe random access occasions may be continued with an adjacent band andthe same available time units. One simple example is illustrated in FIG.8 .

In FIG. 8 , there are 8 random access occasions needed to be mapped intotal, but the available time units of the random access occasions aresubframes 1, 2, 3, 5, and the mapping manner is as illustrated in FIG. 8. the random access occasion with index of 0 is associated to thesubframe 1 in one band, the random access occasion with index of 1 isassociated to the subframe 2 in this band, the random access occasionwith index of 2 is associated to the subframe 3 in this band, the randomaccess occasion with index of 3 is associated to the subframe 5 in thisband, the random access occasion with index of 4 is associated to thesubframe 1 in a next adjacent band, the random access occasion withindex of 5 is associated to the subframe 2 in the next adjacent band,the random access occasion with index of 6 is associated to the subframe3 in the next adjacent band, and the random access occasion with indexof 7 is associated to the subframe 5 in the next adjacent band.

It should be noted that the available time unit of the random accessoccasion described above should be understood as the index of the firsttime unit of the random access occasions. In the preamble sequenceformat utilized actually, the single entire preamble sequence may occupya plurality of time units. The time unit may be the subframe, the slot,a mini slot or the symbol.

In the above descriptions, the mapping in the frequency domain is in aform of continuous mapping.

In other possible implementations, the mapping in the frequency domainmay be in a form of hopping. For example, an index n_(w) of physicalresource block in wth available band is specified as:

$n_{w} = \left\{ \begin{matrix}{{n + \frac{w_{{msg}1}w}{2}},{w{is}{an}{even}}} \\{{N_{UL} - \left( {n + {{w_{{msg}1}\left( {w + 1} \right)}/2}} \right)},{w{is}{an}{odd}}}\end{matrix} \right.$

Wherein N_(UL) is a number of the physical resource blocks included inallocated uplink bandwidth. The uplink bandwidth may be entire availableuplink bandwidths, or may be an available bandwidth dedicated totransmit the random access channel.

It should be noted that meanings of the density and the number of theavailable random access channels in the frequency domain included in therandom access channel configuration information are as follows.

According to the time-frequency resource information and the density inthe random access channel configuration information, the terminaldetermines a plurality of random access channels (each random accesschannel would include a plurality of random access occasions) in thetime domain, that is, one synchronization signal block may associate aplurality of random access occasions in the different random accesschannels. The terminal may select the random access occasions totransmit the preamble sequences according to the predeterminedcriterions. One possible criterion may be set to select the randomaccess occasion with a minimum delay to transmit the preamble sequences;another possible criterion may be set to select the random accessoccasion in the current radio frames, or the subframes or the slots atan equal probability to transmit the preamble sequences.

According to the time-frequency resource information and the number ofthe available random access channels in the random access channelconfiguration information, the terminal determines a plurality of randomaccess channels (each random access channel would include a plurality ofrandom access occasions) in the frequency domain, that is, onesynchronization signal block may associate a plurality of random accessoccasions in the different random access channels. The terminal mayselect the random access occasions to transmit the preamble sequencesaccording to the predetermined criterions. One possible criterion may beset to select the random access occasion at an equal probability totransmit the preamble sequences.

Second Embodiment

A indication manner of the physical random access channel configurationinformation would be discussed in connection with a detailed system inthe present embodiment. Assumptions for the present embodiment is asthose as for the First Embodiment. That is: the differentsynchronization signal blocks are assumed to use different downlinktransmitting beams; the association is assumed to be implemented in thepreset manner, namely the association is known by the base station andthe terminal; the random access channel is assumed to be consisted ofthe plurality of random access occasions, and one random access occasionis used to transmit the preamble sequences defined by one random accesspreamble sequence format.

The First Embodiment (as illustrated in FIGS. 2-8 ) specifies anone-to-one relationship of association between the synchronizationsignal blocks and the random access occasions. In the presentembodiment, the plurality of synchronization signal blocks may beassociated to a plurality of same or different random access occasions.Regarding a case where the plurality of synchronization signal blocksare associated with the one same random access occasion, its exemplarybanding manner may be as illustrated in FIG. 9 . FIG. 9 is an exemplaryview illustrating the case where the plurality of synchronization signalblocks are associated with the same random access occasion according tothe second embodiment of the present disclosure, wherein a mappingrelationship exists between the plurality of synchronization signalblocks and the one random access occasion.

In FIG. 9 , every two synchronization signal blocks are associated withthe one random access occasion.

In the present embodiment, the manner for acquiring the random accesschannel configuration by the terminal is similar to that of the FirstEmbodiment. The terminal acquires the optimal synchronization signalblock according to the downlink measurement result at first; theterminal reads the index of the synchronization signal block, and therandom access channel configuration information and the preamblesequence resource pool information carried therein; the terminal selectsthe preamble sequence from the preamble sequence resource pool, anddetermines the time-frequency resource of the random access occasionaccording to the random access channel configuration information and theassociation between the synchronization signal blocks and the randomaccess occasions.

In the present embodiment, the random access channel configurationinformation transmitted in the respective synchronization signal blocksis same. That is to say, both the MIBs in the broadcast channel and theSIBs indicated by the MIBs transfer same contents.

If the association between the synchronization signal blocks and therandom access occasions is determined in the predetermined manner, it isdefined that the number of the synchronization signal blocks associatingwith the same random access occasion is S and the random accessoccasions is assigned in the time domain first criterion. If the indexof the synchronization signal block starts from 0 and the number ofavailable random access occasions in the time domain is M_(RO), the timedomain index of the random access occasion associated with thesynchronization signal block n_(SS) is calculated as:

m _(RO)=mod(└n _(SS) /S┘,M _(RO)),

and the frequency domain index of the random access occasion associatedwith the synchronization signal block n_(SS) is calculated as:

n _(RO) =└└n _(SS) /S┘/M _(RO)┘.

In another manner for determining the random access occasions, therandom access occasions are assigned in the frequency domain firstcriterion. If the index of the synchronization signal block starts from0, and the number of available random access occasions in the frequencydomain is N_(RO), the time domain index of the random access occasionassociated with the synchronization signal block n_(SS) is calculatedas:

m _(RO)=mod(└n _(SS) /S┘,N _(RO)),

and the frequency domain index of the random access occasion associatedwith the synchronization signal block n_(SS) is calculated as:

n _(RO) =└└n _(SS) /S┘/N _(RO)┘.

The terminal may obtain the time-frequency position of the random accessoccasion after it obtains the index of the random access occasion in therandom access channel. The detailed method may refer to the methoddescribed in the First Embodiment, and details are omitted here.

If the association between the synchronization signal blocks and therandom access occasions is determined in a configured manner, theinformation on the number of the synchronization signal blocksassociated with the same random access occasion is added to the randomaccess channel configuration information. An index table of the randomaccess channel configuration with such manner is as shown in Table 3below.

TABLE 3 example of index table of a further random access channelconfiguration Density of Number of Number Of Preamble Random RandomRandom Access Time-Frequency Number Of Sequence Access Access OccasionsIn Resource Synchronization Index Format Channel Occasions Time DomainInformation Signal Blocks 0 0 0.5 8 4 (t₀, n₀) 1 1 0 1 16 8 (t₁, n₁) 1 21 1 8 8 (t₂, n₂) 2 3 1 2 16 8 (t₃, n₃) 2 . . . . . . . . . . . . . . . .. . . . .

In the example shown in Table 3, a parameter representing the number ofthe synchronization signal blocks is added. This parameter should beunderstood as the number of the synchronization signal blocks associatedwith the same random access occasion.

In this case, the terminal may acquire the parameters for thetime-frequency resources of the random access occasions according to therandom access channel configuration, and acquire the time-frequencypositions of the random access occasions in accordance with the processdescribed above.

Third Embodiment

A indication manner of the physical random access channel configurationinformation would be discussed in connection with a detailed system inthe present embodiment. Assumptions for the present embodiment is asthose as for the First Embodiment. That is: the differentsynchronization signal blocks are assumed to use different downlinktransmitting beams; the association is assumed to be implemented in thepreset manner, namely the association is known by the base station andthe terminal; the random access channel is assumed to be consisted ofthe plurality of random access occasions, and one random access occasionis used to transmit the preamble sequences defined by one random accesspreamble sequence format; and as the association between thesynchronization signal blocks and the random access occasions, the onesynchronization signal block is assumed to have the mapping relationshipwith one random access occasion.

In the present embodiment, the manner for acquiring the random accesschannel configuration by the terminal is similar to that of the FirstEmbodiment. The terminal acquires the optimal synchronization signalblock according to the downlink measurement result at first; theterminal reads the index n_(SS) of the synchronization signal block, andthe random access channel configuration information and the preamblesequence resource pool information carried therein; the terminal selectsthe preamble sequence from the preamble sequence resource pool, anddetermines the time-frequency resource of the random access occasionaccording to the random access channel configuration information and theassociation between the synchronization signal blocks and the randomaccess occasions.

In the present embodiment, the information transmitted in the respectivesynchronization signal blocks may be different. In a firstimplementation of the present embodiment, the information provided bythe random access channel configuration information comprises contentssuch as the random access preamble sequence format supported by therandom access channel configuration, the time-frequency resourceinformation of the random access channel, etc. The random access channelconfiguration information is same all over the synchronization signalblocks. That is, the same system utilizes the same random access channelconfiguration information.

Besides the random access channel configuration information, thesynchronization signal block carries the offset of the time-frequencyposition of the random access occasion associated with thesynchronization signal block, with respect to the time-frequencyposition provided in the random access channel configuration.Particularly, the offset of the time-frequency resource may berepresented as the number of the time units and the number of thephysical resource blocks. For example, the information carried in thesynchronization signal block n_(SS) comprises: the random access channelconfiguration information, the random access preamble sequence resourcepool information and the time-frequency offset of the random accessoccasion associated with the synchronization signal block n_(SS). Theoffset information may be carried by the MIBs in the broadcast channelor the SIBs indicated by the MIBs.

Below will describe a simple example. If the time-frequency resourceinformation provided in the random access channel configurationinformation is (t, n) while the offset information carried in thesynchronization signal block n_(SS) is t_(SS) and n_(SS), the timedomain position of the random access occasion associated with thesynchronization signal block n_(SS) is t+t_(SS) and the frequency domainposition is n+n_(SS) It should be noted that the time domain position ofthe random access occasion should be understood as the time unit indexof the first time unit of the random access occasion, and the frequencydomain position should be understood as the index of the physicalresource block.

The terminal reads the random access channel configuration informationand the corresponding offset information from the synchronization signalblock, determines the time-frequency resource of the random accessoccasion associated with the synchronization signal block, selects thepreamble sequence from the preamble sequence resource pool read from thesynchronization signal block, generates the preamble sequence accordingto the preamble sequence format in the random access channelconfiguration information, and transmits the same in the correspondingrandom access occasion.

In a second implementation of the present embodiment, the random accesschannel configurations carried in the different synchronization signalblocks are not same, and the time-frequency resource information in therandom access channel configuration may represent the time-frequencyresource information of the random access occasion associated with thesynchronization signal block.

After reading the random access channel configuration, the terminal candirectly acquire the position information of the time-frequency resourceof the random access occasion associated with the synchronization signalblock and transmit the preamble sequence on the time-frequency resource.

In this case, the content of the random access channel configurationinformation should at least include the format of the random accesspreamble sequence, the time-frequency resource of the random accessoccasion and density of random access channel and etc.

It should be noted that the above random access channel configuration isgiven in a form of look-up table and only index of the correspondingconfiguration is indicated as indication. Another indication manner isto indicate the contents of the random access channel configuration insignaling directly.

Fourth Embodiment

A indication manner of the physical random access channel configurationinformation would be discussed in connection with a detailed system inthe present embodiment. In the present embodiment, it is assumed thatthe random access channel configuration information is transmitted on aRemaining Minimum System Information (RMSI) and contents of the RMSI onthe different downlink signals (corresponding to the different downlinkbeams) are same.

Embodiments described previously briefly introduce configuring of theassociation between the downlink signals (such as the downlinksynchronization blocks) and the random access occasions. The presentembodiment indicates the corresponding association in a manner ofdisplaying a indication. Meanwhile, the association may be indicatedtogether with the random access channel configuration information, as apart of the random access channel configuration (for example, by addinga new field for indicating the association between the indices of thedownlink signals and the random access occasions) or as an independentsignaling. These two indication manners have no essential differences,and the present embodiment will explain the first manner, namely themanner of carrying the indication of the association in the randomaccess channel configuration information, as an example.

In the present embodiment, an indication of the information on therandom access occasions associated with the each synchronization signalblock is displayed. Wherein the information on the random accessoccasion is the resource index of the random access occasion which isconfigured in a predetermined manner or is determined in a predeterminedcriterion. The information on the random access occasion may furthercomprise the subframe index of the random access occasion and a PRBindex with which the time-frequency resources of the available randomaccess occasions may be determined.

A possible manner of displaying the indication is to establish a look-uptable as shown in Table 4 below, and obtain the information on thecorresponding random access occasion through the downlink signal index(for example, the index of the synchronization signal block or an indexof a possible CSI-RS.

TABLE 4 relationship table for downlink signal index and information onrandom access occasion. Index Of Downlink Signal Information On RandomAccess Occasion 0 Information 0 1 Information 1 2 Information 2 . . . .. .

The above table may be indicated in a form of tuple, that is, theindication is in a form of (n_(SS),n_(PRACH)) wherein n_(SS) is theindex of the downlink signal, and n_(PRACH) is the information on therandom access occasion. In a further indication manner, a sequence ofthe information on the random access occasions is indicated directly,and a number of elements in the sequence is same as the number of thesynchronization signal blocks, each element presents the time-frequencyresource information of the random access occasion corresponding to therespective synchronization signal block.

Another indication manner utilizes a bit map. The number of the randomaccess occasions is fixed to each random access channel configuration.When the association between the synchronization signal blocks and therandom access occasions is indicated, a bit sequence of 0, 1 with alength of the number of the random access occasions is established forthe each synchronization signal block, each element therein representswhether the synchronization signal block corresponds to thecorresponding random access occasion, and it is denoted that the randomaccess occasion with the corresponding index associates with thesynchronization signal block if the element is 1, otherwise does notassociate. For example, for a certain random access channelconfiguration information, if the number of the available random accessoccasions is M, the length of the bit sequence for configuring andindicating the corresponding random access occasions is M, wherein thebit sequence comprises M−1 0s and one 1, and the position of 1 denotesthe index of the random access occasion. When the association isconfigured and indicated in such a manner, each synchronization signalblock requires a bit sequence with the length of M to be established,and a total overhead is in positive proportion to a product of thenumber N of the synchronization signal blocks and the number M of therandom access occasions.

As utilizing the bit map, another manner is to establish a bit sequenceof 0, 1 with a length of the number of the synchronization signal blocksfor each random access occasion, each element therein represents whetherthe synchronization signal block with the corresponding index associateswith the random access occasion. If the element is 1, it is denoted thatthe synchronization signal block with the corresponding index at thisposition associates with the random access occasion, otherwise, it isdenoted un-associating. For example, regarding a system including Nsynchronization signal blocks, a bit sequence with the length of N isestablished for each random access occasion, wherein 0, 1 denote whetherthe synchronization signal block at the corresponding positionassociates with the random access occasion. Taking a bit sequence [0 1 10 0 0 0 0] with the length of 8 as an example, it presents 8synchronization signal blocks existed in total, the elements atpositions 1 and 2 in the bit sequence are 1, which denote that thesynchronization signal blocks with the indices 1, 2 associate with therandom access occasion. When the bit map indication manner is utilized,each random access occasion requires a bit sequence with the length of Nto be established, and a total overhead is in positive proportion to aproduct of the number N of the synchronization signal blocks and thenumber M of the random access occasions.

Another manner of indicating the association between the downlink signalindices and the random access occasions by the bit map is to directlyindicate the indices of the time domain resource and the frequencydomain resource of the random access occasion associated with thedownlink signal by the bit map. For example, an index of a symbol fromwhich the random access occasion associated with the downlink signalstarts in a subframe is indicated using the bit map; meanwhile, an indexof a start PRB of the random access occasion is indicated using the bitmap. Regarding a frame structure including 7 or 14 symbols, a bitsequence with the length 7 or 14 is established for each downlink signal(for example, the synchronization signal block or the CSI-RS), wherein avalue of each bit presents whether the symbol at the correspondingposition is the start symbol of the random access occasion associatedwith the downlink signal. If the bit is 1, it is the start symbol of therandom access occasion, otherwise, it is not. Meanwhile, a bit sequencewith a length of the number of the PRBs available to random accessing isestablished, wherein each element presents whether the symbol at thecorresponding position is the start PRB of the random access occasionassociated with the downlink signal. If the element is 1, the PRB at thecorresponding position is the start PRB, otherwise, it is not.

In another configuration manner, the time domain index is indicated andconfigured in the manner of bit map, and the frequency domain index isindicated with the PRB index.

After adding the above indication of the association, the format of therandom access channel configuration information is as follows:

{a preamble sequence format, a time-frequency resource information ofrandom access channel, an association between synchronization signalblocks and random access occasions}.

The above format is indexed and numbered, and transmitted to theterminal in a form of number. When the association between thesynchronization signal blocks and the random access occasions isindicated by the index of the random access channel configuration, thepossible indices may be many. In another indication manner, only thepreamble sequence format and the time-frequency resource information ofthe random access channel is indicated for the random access channelconfiguration, and the association between the synchronization signalblocks and the random access occasions is indicated separately with theindex of the random access channel configuration. Such indication mannercan establish the association between the synchronization signal blocksand the random access occasions flexibly. It should be noted that thetime-frequency resource information of the random access channeldescribed previously comprises the implementations of the time-frequencyresource information in the previous embodiments.

Fifth Embodiment

In the present embodiment, an indication manner of the physical randomaccess channel configuration information will be discussed. In thepresent embodiment, the base station is assumed to operate withmulti-beam or single-beam. For the multi-beam operation, the downlinksynchronization signal and the broadcast channel are transmitted in amanner of a plurality of synchronization signal blocks. Wherein eachsynchronization signal block is transmitted via one downlinktransmission beam, and the downlink transmitting beams utilized for thedifferent synchronization signal blocks may be same or not. For thesingle-beam operation, transmitting of the downlink synchronizationsignal and the broadcast channel are completed via one synchronizationsignal block or a periodic repetition of the one synchronization signalblock. Each synchronization signal block comprises a primarysynchronization signal, a secondary synchronization signal and abroadcast channel bearing the MIBs. Other necessary information foraccessing the system is transmitted in the RMSI. The contents in theRMSI indicated and transmitted in the different synchronization signalblocks are same.

The method provided by the present embodiment is applicable to both theabove base stations operating with the multi-beam and the single-beam,and provides a certain flexibility of the system without introducingapparent redundant signaling. A general concept of the solution providedby the present embodiment is in that: the random access channelconfiguration information transmitted is adjusted according to thenumber of the synchronization signal block transmitted actually, so thatthe manner according to the present embodiment can be applicable to thesystem of the single-beam operation as well as the system of themulti-beam operation wherein the number of the synchronization signalblocks transmitted actually varies.

One possible implementation is to indicate possible configurationsdirectly instead of indicating the physical random access channelconfiguration information via the index of the look-up table. Meanwhile,the random access channel configuration information for the differentsynchronization signal blocks may be different, and indicated in amanner of enumeration. The random access channel configurationinformation for each synchronization signal block may comprise:

-   -   a format information of the random access preamble sequence;    -   a time domain index of the random access occasion;    -   a time domain density/period of the random access occasion;    -   a frequency domain index of the random access occasion; and    -   a number of the random access occasions in the frequency domain.

Meanings of the respective parameters in the above random access channelconfiguration information are as follows. The preamble sequence formatdefines an interval of subcarriers in the random access channel, asequence repetition number of the preamble sequence utilized or a numberof the sequences, and a length of Cyclic Prefix. Based on suchinformation, the terminal can acquire a duration in the time domain anda bandwidth in the frequency domain of the random access occasion.

The time domain index of the random access occasion may be indicated viaan index of a start time unit of the random access occasion, forexample, an index of a start subframe or an index of a start slot, or anindex of a mini slot, or an index of a start symbol, of the randomaccess occasion. The time domain density/period of the random accessoccasion specifies a frequency domain in which the random accessoccasion associated with the synchronization signal block occurs. Thisparameter may be configured as follows: the number of the random accessoccasions occurred in a set of time units, or a number of the time unitswithin an interval between two adjacent random access occasionsassociated with the synchronization signal block. Wherein the set of thetime units may be a set of a plurality of continuous time units. Forexample, if the time unit is represented by the symbol, the set of timeunits is the slot or mini slot; if the time unit is represented by theslot or the mini slot, the set of time units is the subframe; and if thetime unit is represented by the subframe, the set of the time units isthe ratio frame.

The frequency domain index of the random access occasion may beindicated via the index of the start physical resource block of therandom access occasion. The number of the random access occasions in thefrequency domain is used to indicate the number of the random accessoccasions in the frequency band for the uplink random accessing. Theparameter may be replaced with the number of the physical resourceblocks within an interval between two adjacent random access occasionsin the frequency domain.

The series of parameters described above can determine a structure andthe time-frequency resources of the random access occasions associatedwith the synchronization signal block. The terminal can acquire thetime-frequency resources of the random access occasion completely afteracquiring the above parameters.

The parameters for determining the time-frequency resource for therandom access occasion may be replaced with other parameters as follows:for the time domain parameters (including the time domain index of therandom access occasion and the density/period of the random accessoccasion) may be replaced with the available time units within the setof the time units. For example, if the time unit is represented as thesubframe, the index of the available subframe within the unit radioframe is indicated; if the time unit is represented as the slot/minislot, the available slot or mini slot within the unit subframe isindicated; if the time unit is represented as the symbol, the availablesymbol within the unit slot is indicated. One or more available timeunits exist in the set of the time units and are indicated via a vectoror a sequence.

For the frequency domain parameters (including the frequency domainindex of the random access occasion and the number of the random accessoccasion in the frequency domain) may be determined in followingmanners. One manner is to indicate the index of the first physicalresource block of the available random access occasion, and theindication and configuration are in a form of index sequence.Alternatively, the number of the physical resource blocks within theinterval between two adjacent random access occasions is indicated.Another manner is to determine the frequency domain resource accordingto predetermined rules. For example, it is specified in advance that theresource mapping is in a time domain first manner, the number of thephysical resource blocks within the interval between the two adjacentrandom access occasions in the frequency domain is specified andindicated, the number of the available random access occasions withinthe set of the time units and the index of the available time unitswithin the set of the time units are indicated. After receiving theabove information, the terminal maps in the time domain according to thegiven frequency domain indices at first, and if the number of theindices of the available time units is smaller than the number of therandom access occasions, determines a next available frequency domainposition according to the available frequency domain indices or theinterval between the physical resource blocks of the adjacent randomaccess occasions in the frequency domain after the indices of the unitsin the time domain end, and performs the time domain mapping at thefrequency domain position until the time-frequency resources aredetermined for all of the random access occasions.

The above parameters are required to be configured and indicated foreach synchronization signal block, and the random access channelconfiguration information comprises parameters as follows:

-   -   the indices of the synchronization signal blocks;    -   the preamble sequence format; and    -   related information on the time-frequency resource of the random        access occasion.

Wherein the related information on the time-frequency resource of therandom access occasion comprises the parameters for determining thetime-frequency resource of the random access occasion described above.The random access channel configuration information may be indicated ina following manner:

the number N of the synchronization signal blocks;

{index 0 of the synchronization signal block, preamble sequence format,time-frequency resource of random access occasion};

{index 1 of the synchronization signal block, preamble sequence format,time-frequency resource of random access occasion};

. . .

{index N−1 of the synchronization signal block, preamble sequenceformat, time-frequency resource of random access occasion}.

That is, the configuration information of the random access occasionscorresponding to the N synchronization signal blocks is indicated in theform of enumeration. Furthermore, the number N of the synchronizationsignal blocks is the number of the synchronization signal blockstransmitted actually, and may be transmitted separately or in the MIB.

The configuration and indication manner described above would lead to agreat overhead when the number of the synchronization signal block islarge. One efficient manner for reducing the overhead is to extract acommon part(s). If the random access occasions corresponding to thedifferent synchronization signal blocks use a same preamble sequenceformat, it may be indicated in a following manner:

the number N of the synchronization signal blocks;

the preamble sequence format;

{index 0 of synchronization signal block, time-frequency resource ofrandom access occasion};

{index 1 of synchronization signal block, time-frequency resource ofrandom access occasion};

. . .

{index N−1 of synchronization signal block, time-frequency resource ofrandom access occasion}.

Wherein the number N of the synchronization signal blocks is the numberof the synchronization signal blocks transmitted actually, and may betransmitted separately or in the MIB.

If the time-frequency resource information of the random accessoccasions corresponding to the different synchronization signal blockshas a common part, the common part may be also extract to savesignaling. For example, if the random access occasions corresponding tothe different synchronization signal blocks uses the same frequencydomain resources, the indication manner is as follows:

the number N of the synchronization signal blocks;

the preamble sequence format;

the frequency domain index;

the number of the random access occasions in the frequency domain;

{index 0 of synchronization signal block, time domain positioninformation of random access occasion};

{index 1 of synchronization signal block, time domain positioninformation of random access occasion};

. . .

{index N−1 of synchronization signal block, time domain positioninformation of random access occasion}.

Wherein the number N of the synchronization signal blocks is the numberof the synchronization signal blocks transmitted actually, and may betransmitted separately or in the MIB. The frequency domain index and thenumber of the random access occasions in the frequency domain are usedto determine the frequency domain position of the random accessoccasion, and may be replaced with other replacements described above.Additionally, the above example assumes that the random access occasionscorresponding to the different synchronization signal blocks use thesame preamble sequence format which can be indicated commonly.Similarly, the above manner is also applicable to a case where thedifferent random access occasions use the same or different preamblesequence formats, and the preamble sequence formats should not beindicated and configured commonly in this case.

If the random access occasions corresponding to the differentsynchronization signal blocks use the same density, it may be indicatedand configured in a following manner:

the number N of the synchronization signal blocks;

the preamble sequence format;

an indication of the time domain density/period of the random accessoccasion;

{index 0 of synchronization signal block, time domain positioninformation of random access occasion};

{index 1 of synchronization signal block, time domain positioninformation of random access occasion};

. . .

{index N−1 of synchronization signal block, time domain positioninformation of random access occasion}.

Wherein the number N of the synchronization signal blocks is the numberof the synchronization signal blocks transmitted actually, and may betransmitted separately or in the MIB. The above indication manner isalso applicable to a case where the different synchronization signalblocks use the same or different preamble sequence format.

With the above indication and configuration manner, as accessinginitially, the terminal determines the synchronization signal blocksaccording to the measurement result, acquires the configurationinformation of the corresponding random access occasion according to theindices of the synchronization signal blocks (for example, logic indicesof the synchronization signal block, or the time domain indices of thesynchronization signal blocks, which is acquired from the primarysynchronization signal, the secondary synchronization signal andinformation in the MIBs as accessing initially), and transmits thepreamble sequence on the random access occasion.

In the above configuration manner, the synchronization signal blocks areindexed to configure the time-frequency resource of the random accessoccasion. Such manner is more suitable to the case where the one-to-onemapping relationship exists between the synchronization signal blocksand the random access occasions, that is, the different synchronizationsignal blocks are associated to the random access occasion notoverlapping with each other. As to the case where the plurality ofsynchronization signal blocks are associated to the same random accessoccasion, the above configuration manner may be also used but may leadto some redundant signaling.

Another indication manner is to index the random access occasions inorder to configure and indicate. In such a configuration and indicationmanner, the signaling content needed to be configured is as follows:

{time-frequency resource information 0 of random access occasion,preamble sequence format, index of corresponding synchronization signalblock};

{time-frequency resource information 1 of random access occasion,preamble sequence format, index of corresponding synchronization signalblock};

. . .

{time-frequency resource information M−1 of random access occasion,preamble sequence format, index of corresponding synchronization signalblock}.

In the above configuration, the corresponding time-frequency resourceinformation and the corresponding preamble sequence format informationare configured for each random access occasion. Meanwhile, the index ofthe synchronization signal block corresponding to the random accessoccasion is further configured. As to a case where one random accessoccasion is associated with several synchronization signal blocks, anindex sequence of the synchronization signal blocks may be indicated.Further, as to a case where the different random access occasions havethe same parameter(s) (such as the same preamble sequence format, andthe like), the common parameter may be extracted to indicate andconfigure separately.

The above indication manner indicates the actual configurationinformation. Another possible manner may list the possible configurationmanners as an index table including the preamble sequence format and thepreviously mentioned configuration information of the random accessoccasion. When the configuration information of the random accessoccasion is indicated and configured, the indication manner is asfollows:

the number N of the synchronization signal blocks;

{index 0 of synchronization signal block, configuration index 0 ofrandom access occasion};

{index 1 of synchronization signal block, configuration index 1 ofrandom access occasion};

. . .

{index N−1 of synchronization signal block, configuration index N−1 ofrandom access occasion}.

Wherein the number N of the synchronization signal blocks is the numberof the synchronization signal blocks transmitted actually, and may betransmitted separately or in the MIB.

The configuration index table of the random access occasions may be anindex table below.

TABLE 5 example of index table of random access occasion configurationTime-Frequency Index Preamble Sequence Format Resource Configuration 0Format Index 0 Configuration0 1 Format Index 1 Configuration 1 . . . . .. . . . K Format Index K Configuration K

It should be noted that the above table only lists parameters which arepossible to occur in the configuration index table of the random accessoccasion, and the format indices corresponding to the different indicesmay be same, that is to say, for the different indices, the samepreamble sequence format may be used.

In order to further reduce the overhead for the configuration of therandom access channel, different available index range are defined whenthe numbers of the synchronization signal blocks transmitted actuallyare different. A simple example would be discussed. If the number of thesynchronization signal blocks transmitted actually is not greater thanK1, the configuration index range of the available random accessoccasions is 1˜M1; if the number of the synchronization signal blockstransmitted actually is greater than K1 but not greater than K2, theconfiguration index range of the available random access occasions is1˜M2; if the number of the synchronization signal blocks transmittedactually is greater than K2, the configuration index range of theavailable random access occasions is 1˜M3; and so on, until a maximumnumber of the synchronization signal block transmitted is reached.

Related information of the preamble sequence resource pool is notconfigured in the above configuration manner. As to a case where theplurality of the synchronization signal blocks correspond to the samerandom access occasion, the preamble sequences are required to begrouped in order to facilitate the base station to determine thedownlink transmitting beams for transmitting random access responses,and the suitable downlink transmitting beams are indicated to the basestation in the group manner. Group information of the preamble sequencesis required to be indicated together with the configuration informationof the corresponding random access occasion, that is, the random accessoccasion configuration information further comprises the groupinformation of the preamble sequences besides the time-frequencyresource configuration information. The group information may beindicated in following manners:

In each random access occasion configuration information, the startindex or an end index of the preamble sequence is added; or the startindex of the preamble sequence and the number of the preamble sequencesare added;

The respective groups of the preamble sequences are configured at first,one possible manner is to configure a number of the groups of thepreamble sequences and a number of the preamble sequences in the eachgroup;

If a total number of the preamble sequences is known (for example, thenumber of the total preamble sequences is predetermined, or indicated inthe RMSI), only the number of the groups (group number) is needed to beindicated and configured in the random access configuration information.Meanwhile, in the random access occasion configuration information,indices of the groups of the corresponding preamble sequences areindicated. The terminal determines the indices of the preamble sequencesin each group according to the total number of the preamble sequencesand the number of the groups. The terminal determines the information onthe preamble sequence resource pool to be used according to the indicesof groups of the preamble sequences in the corresponding random accessoccasion configuration information.

The above manner is applicable to a case where the numbers of thepreamble sequences included in the different groups of the random accesspreamble sequences are same. As to a case where the numbers of thepreamble sequences included in the different groups are different, thenumber of the preamble sequences in each group may be indicateddirectly. For example, a possible manner is to configure and indicateusing a number vector of the preamble sequences. A simple example is asfollows: the total available preamble sequences are grouped into Sgroups, wherein the number of the preamble sequences included in the ithgroup comprises is s_(i), and the indication manner is to indicate avector of [s₀, . . . , s_(S-1)]. Further, the indices of groups of thecorresponding preamble sequences are added to the random access occasionconfiguration. The terminal determines the preamble sequence resource tobe used according to the group information and the indices of the groupsin the random access occasion configuration information.

If the preamble sequences in the different groups are distinguished viacovering codes (orthogonal or non-orthogonal), only indices of thecovering codes required to be used in the random access occasion isneeded to be added to the random access configuration information.

Sixth Embodiment

In this embodiment, an indication method of a physical random accesschannel configuration information would be explained. In the presentembodiment, the system may operate in a Frequency Division Duplex (FDD)mode or a Time Division Duplex (TDD) mode. For the FDD mode, thefrequency bands are separated for the uplink and the downlink, and allof the uplink time-frequency resources are considered as being availableas configuring the random access channel; and for the TDD mode, thefrequency bands are shared by the uplink and the downlink, and not allof the uplink time-frequency resources can be considered as beingavailable as configuring the random access channel. Therefore, differentconfiguration methods are required for these two different duplex modes,or different optimization processing's are performed for a sameconfiguration method.

At first, a configuration method of the random access channel for theFDD mode system will described briefly. In the present embodiment, theconfiguration of the random access channel is indicated and configuredby means of a random access channel configuration index table. Inparticularly, the random access channel configuration index table maycomprise: a physical random access channel configuration index, apreamble sequence format index, a radio frame index (or a random accesschannel period), a slot index and any other possible parameters.

Wherein, when the random access channel configuration information isindicated, the base station may only indicate the physical random accesschannel configuration index, and the terminal may determine theconfiguration information according to the index; the preamble sequenceformat index is to determine the preamble sequence format, so that thetime-frequency domain structure of the random access occasion may bedetermined; the radio index is to determine a period of the randomaccess channel; the slot index is to determine the slot index (indices)at which the random access channel may locate within one random accesschannel period.

The present disclosure determines the slot index available for therandom access channel within one random access channel period by aformulaic manner. A subcarrier interval available for the random accesschannel is an integral multiple of 15 kHz, and is represented asfollows: SCS=15*2^(u) kHz, wherein u=0, 1, 2, . . . is an integer notsmaller than 0.

According to the method provided in the present disclosure, theavailable slot index is determined based on a reference subcarrierinterval at first, and then corresponding slot indices under othersubcarrier intervals are determined according to a relationship betweenthe other subcarrier intervals and the reference subcarrier interval.For example, given the reference subcarrier interval being 15 kHz, ifthe slot index is (a, b, c) under a certain physical random accesschannel index, namely the slot a, the slot b and the slot c may be usedin the transmission of the random access channel, the available slotindex under the same physical random access channel index in the othersubcarrier interval (15*2^(u) kHz) is: (a,b,c)+10*i, i=0, . . . , 2^(u).

The above manner may be described as follows: for one physical randomaccess channel index, the available slot index within one period is(a,b,c)+10*i, i=0, . . . , 2^(u).

If it is specified that the slots within first k ms are unavailable forthe random access process, the available slot index quantified accordingto the subcarrier interval may be in a manner that: given the referencesubcarrier interval of 15 KHz, if the slot indices are (a,b,c) under acertain physical random access channel index, that is, the slot a, slotb and slot c may be utilized for the transmission in the random accesschannel, the available slot index under the same physical random accesschannel index in the subcarrier interval of 15*2^(u) kHz is:(a,b,c)*u+10*i, i=0, . . . , 2^(u)−1.

The available random access channel period may comprise 10 ms, 20 ms, 40ms, 80 ms and 160 ms. For the period being greater than 10 ms, onlypositions of the 10 ms frames for the transmission of the random accesschannel are specified. For example, for the period of 20 ms, the 10 msframes for the transmission of the random access channel within 20 msmay be configured by specifying the available slot index as odd or even;and for other available periods, a possible manner may specify the frameindex by a following manner.

For 40 ms, the available frame index is mod(Nf,4)=k, wherein Nf is theframe index, k is an integer within 0˜3, and the available frame indexmay be determined by determining k.

For 80 ms, the available frame index is mod(Nf,8)=k, wherein Nf is theframe index, k is an integer within 0˜7, and the available frame indexmay be determined by determining k.

For 160 ms, the available frame index is mod(Nf,16)=k, wherein Nf is theframe index, k is an integer within 0˜15, and the available frame indexmay be determined by determining k.

The above manner may also be applied to the period of 20 ms, that is,the available frame index is mod(Nf,2)=k, wherein Nf is the frame index,k is an integer within 0˜1, and the available frame index may bedetermined by determining k.

In other words, the random access channel period and the available frameindex may be determined by the above manner, that is, by determining theparameter k in advance.

Another possible manner is in that: the available period index withinthe period is determined by a predetermined manner, and only the periodis indicated in the random access channel configuration index. Forexample, a possible method is to only specify that the transmission ofthe random access occasion is completed within the first 10 ms in oneperiod. In this case, only the actual random access channel period isrequired to be indicated.

The above descriptions are aimed to the random access configurationmanner of the FDD mode. For the TDD mode, the random accessconfiguration manner designed for the FDD mode may be multiplexed whilesome explanations and modifications are needed. Particularly, when acertain downlink/uplink configuration manner is configured, the slotindices are determined for the available uplink time-frequencyresources, and continuous virtual indices of the available uplink slotsare obtained. For example, an uplink/downlink configuration isillustrated as FIG. 18 , and actual indices of the uplink slots are{2,3,4,7,8,9}. The virtual indices of these six slots are {0,1,2,3,4,5}.

The slot index of the physical random access channel in theuplink/downlink configuration may be determined according to the virtualindex and the available slot index in the physical random access channelconfiguration.

It should be further noted that, the index table used for the physicalrandom access channel configuration may be shared by the FDD mode andthe TDD mode, and the FDD mode may utilize one part of configurationindex therein while the TDD mode may utilize the other part ofconfiguration index therein. With the above manner of virtual slotindex, the physical random access channel configurations for the FDDmode and the TDD mode are completed. For some special slot (for ahandover to the uplink from the downlink) in the TDD mode, there are twoprocessing methods as follows.

1. The special slot(s) would not be considered as the available uplinkslot for the random access channel; and

2. The special slot(s) is considered as the available uplink slot forthe random access channel, but a limitation is made for a position ofits start symbol, for example, a start position of the random accesschannel in the special slot is fixed to start from a symbol 2.

The above parameters may determine the slot resources usable for therandom access channel, but additional specifications are still requiredfor the position of the start symbol of the random access channel insidethe slot. A simple manner is to determine the position of the startsymbol in each available slot by a predetermined manner. For example,the position of the start symbol in the each available slot is definedas 0, and each random access channel is arranged from the 0^(th) symbolin all available slots of the random access channels; alternatively, forthe FDD mode and the TDD mode, two modes are predefined for the positionof the start symbol, and different positions of the start symbol areused in the different modes. For example, for the FDD mode, the positionof the start symbol in the each available slot is denoted as 0; and forthe TDD mode, the position of the start symbol in the each availableslot is denoted as 2.

In order to support more flexible positions of the start symbol, theposition of the start symbol in the available slot may be configured andindicated by a manner of look-up table. For example, the position of thestart symbol of the available slot may be defined by a look-up table asshown in Table 6.

TABLE 6 Definition of Position of Start Symbol′ Index Position of StartSymbol 0 0 1 2 2 (0, 2) . . . . . .

In the above table, a multi-component manner of the position of thestart symbol may denote that a plurality of positions may be used forthe transmission of the random access channel in one slot.

The above configuration and indication of the position of the startsymbol may be implemented by adding indices to the physical randomaccess channel configuration index table, and configuring the positionof the start symbol in the available slot also by the physical randomaccess channel configuration index; in another manner, the position ofthe start symbol is configured and indicated by separate parameters.

It should be noted that, for the random access configuration manner witha plurality of available slots, the same or different positions of thestart symbol may be configured to the respective available slots. If thedifferent positions of the start symbol are configured to the differentslots, the configuration and indication may be made by a manner of indexcombination. For the TDD mode, the position of the start symbol may beseparately configured to the special slot. That is, the same position ofthe start symbol is utilized for remaining uplink slots except for thespecial slot, and the position of the start symbol adapted touplink/downlink symbol arrangement is configured for the special slot.Or, for the special slot, a predetermined configuration of the positionof the start symbol is used, instead of using of a indicated startsymbol configuration.

Seventh Embodiment

The present embodiment would describe a method for configuring therandom access channel for a system operating in the TDD mode. Asillustrated in FIG. 10 , it is assumed that the system operates in a TDDframe structure as follows.

In FIG. 10 , one downlink-uplink transmission period comprises aplurality of slots, these slots include X1 uplink slots, Y1 downlinkslots, and remaining slots include X2 uplink symbols and Y2 downlinksymbols, remaining symbols are flexible symbols, and transmissiondirections of the symbols are determined by a Base Station (BS)'sconfiguration. In a data transmission, the BS may completely determinethe frame structure of the TDD in the data transmission by configuringparameters such as the downlink-uplink transmission period, X1, X2, Y1and Y2.

In the present embodiment, following information may be acquired by therandom access channel configuration index: a preamble sequence format, alength of Cycle Prefix (CP) including the preamble sequence, a length ofsequence, repeat times of the sequence, and the like; the configurationperiod of the random access channel, including options such as 10 ms, 20ms, 40 ms, 80 ms, etc.; slot index that may occur in the random accesschannel, may be a single index or an index combination; a system frameat which the random access channel may be configured in the randomaccess configuration period, may be obtained by the modulo operationperformed on 1 (for the 10 ms period), or 2 (for the 20 ms period), or 4(for the 40 ms period) or 8 (for the 80 ms period) with respect to asystem frame number, and other configuration periods are similar; astart symbol index in the slot; a number of the slots capable ofconfiguring the random access channel; and a number of the random accessoccasions in one random access slot (related to the random accesspreamble sequence format).

For the random access, because the terminal has not access to thenetwork, it may not determine the frame structure as shown in FIG. 10 ,and it is difficult to ensure no conflict occurred between the randomaccess channel and the downlink channel. In order to settle suchproblem, the present embodiment proposes possible schemes as follows.

For the TDD frame structure as shown in FIG. 10 , the downlink-uplinktransmission period is configured and indicated in the SystemInformation or Remaining Minimum System Information (RMSI), and themapping of the time-frequency resources of the random access channel aredefined as follows:

considering an end of each available uplink slot in the random accesschannel as a reference time, a time K_(RA) is shift forward according tothe random access configuration information and the preamble sequenceformat, as a starting point for transmitting the random access occasion.

The time K_(RA) may be according to several manners as follows.

1a. The parameter K_(RA) is educed by taking the length of CP, thelength of sequence and the number of the random access occasionsincluded in the random access slot and the like defined in the randomaccess preamble sequence format into account. In particular, theparameter K_(RA) may calculated as:

K _(RA)=(N _(CP) +N _(seq))*N _(RO),

wherein N_(CP) is the length of CP, N_(seq) is the length of sequence,and N_(RO) is the number of the random access occasions in the randomaccess slot.

The above manner is illustrated as in FIG. 11 .

In an example illustrated in FIG. 11 , the random access slot comprisesthree random access occasions, and a length of the each random accessoccasion in time domain is defined by the length of CP and the length ofsequence. The terminal may consider the end of the uplink slot as thereference time and educe the starting point for transmitting the randomaccess channel forward based on the reference time.

In a case where the uplink slot comprises a plurality of random accessslots, the above manner may be applied to each of the random accessslots, that is, by considering the end of the random access slot as thereference time and deducing the starting time of the random accesschannel forward.

In a case where a random access start symbol index is N_(start) in therandom access channel configuration, symbols in the uplink slot arenumbered in an order from back to front, and the start time of therandom access channel is educed forward from the end of the symbol withthe index of N_(start) as illustrated in FIG. 12 .

In FIG. 12 , the index of the start symbol is 2, the symbols in therandom access slot are numbered in the order from back to front, and thestart time of the random access channel is educed forward from the endof the symbol 2. Another method is to determine an end of the randomaccess channel in that: for the uplink slot including N_(sym) symbols,the starting point of the random access channel is educed forward fromthe end of the symbol N_(sym)-1-N_(start). For example, in the aboveexample, in a case of N_(sym)=14 symbols and N_(start)=2, the startingpoint of the random access channel is educed forward from the end of thesymbol 11.

For the random access slot wherein several preamble sequence formats arecombined, the starting point of the random access channel in time domainis educed forward in a manner as follows, based on the end of the randomaccess uplink slot or according to the start symbol index:

K _(RA)=Σ_(i)(N _(CPi) +N _(seqi))*N _(ROi),

wherein N_(CPi) is the length of CP for the ith preamble sequenceformat, N_(seqi) is the length of sequence for the ith preamble sequenceformat, and N_(ROi) is the number of the random access occasions for theith preamble sequence format. Parameter i is counted from 1 to types ofthe preamble sequences.

For example, for a combination of preamble sequence formats A1 and B1,if one random access slot comprises 6 random access occasions, the first5 use the preamble sequence format A1 and the last one uses the preamblesequence format B1, then the start time may be educed as:

K _(RA)=(N _(CP_A1) +N _(seq_A1))*5+(N _(CP_B1) +N _(seq_B1)).

1b. The parameter K_(RA) is educed by taking the length of CP, thelength of sequence, the number of the random access occasions includedin the random access slot and the like defined in the random accesspreamble sequence format and a guard time into account. In particular,the parameter K_(RA) may calculated as:

K _(RA)=(N _(CP) +N _(seq))*N _(RO) +N _(GT),

wherein N_(CP) is the length of CP, N_(seq) is the length of sequence,N_(RO) is the number of the random access occasions in the random accessslot, and N_(GT) is a length of the guard time.

The above manner is illustrated as in FIG. 13 .

Because neither the current preamble sequence format nor the currentrandom access channel configuration information includes the length ofthe guard time, the length of the guard time may be acquired byfollowing possible manner if the start time of the random access channelis educed in the manner described in the present embodiment:

-   -   the BS adds an indication and configuration of the guard time to        the random access channel configuration information or the        preamble sequence format;    -   the terminal educes the guard time according to a data structure        of data channels and the random access channel. For example, the        length of the guard time may be educed according to a channel        structure (including the subcarrier interval, a length of CP in        the data channel, a length of symbol, etc.) of an initial uplink        channel including the random access channel, and the preamble        sequence format.

After acquiring the above parameters, based on the end of the uplinkslot, the start time of the random access channel may be educedaccording to the above parameters and the start symbol index.

If several preamble sequence formats may be transmitted in the randomaccess slot, the start time of the random access channel may be educedaccording to a number of each type of the preamble sequences, as shownin an equation below:

$K_{RA} = {{\sum\limits_{i}{\left( {N_{CPi} + N_{seqi}} \right)*N_{ROi}}} + N_{GT}}$

wherein N_(CPi) is the length of CP for the ith preamble sequenceformat, N_(seqi) is the length of sequence for the ith preamble sequenceformat, and N_(ROi) is the number of the random access occasions for theith preamble sequence format. Parameter i is counted from 1 to types ofthe preamble sequences, and N_(GT) is the length of the guard time.

In the method described above, if a time advance and/or a time advanceoffset for the random access is not zero, the transmitting startingpoint of the random access channel in time domain may be further educedaccording to the time advance and/or the time advance offset based onthe start position above-described.

For example, if the time advance and the time advance offset are notzero, then:

T _(RA) =K _(RA) +N _(TA) +N _(RA-offset),

wherein N_(TA) is the time advance for the random access, N_(TA-offset)is the time advance offset for the random access process. However, bothof the N_(TA) and N_(TA-offset) in the above equation may also be zero.

2. For the TDD frame structure illustrated in FIG. 10 , thedownlink-uplink transmission period and a number X1 of uplink slots areconfigured and indicated in the System Information or the RemainingMinimum System Information (RMSI). According to such parameters, theterminal may acquire the start position of the uplink slot. Thetime-frequency resources of the random access channel are selected andmapped with the start position as a starting point. This method is asillustrated in FIG. 14 .

In a case where a plurality of available random access slots areincluded, the starting point of each random access slot is considered asthe starting point of the random access channel in time domain.

Particularly, the present method considers the starting point of each ofthe available uplink slots as the start position of the random accesschannel.

In the method described above, if a time advance and/or a time advanceoffset for the random access is not zero, the transmitting startingpoint of the random access channel in time domain may be further educedaccording to the time advance and/or the time advance offset based onthe start position above-described.

3. A combination of two methods described above. The BS configures andindicates the downlink-uplink transmission period and the number X1 ofthe uplink slots in the System Information or RMSI. The terminalacquires the start position of the uplink slots according to the periodinformation and the number of the uplink slots. The manner fordetermining the start position of the random access channel in method 1is utilized for the first uplink slot in the downlink-uplinktransmission period, that is, the end of the uplink slot is consideredas the reference time, and the starting point position of the randomaccess channel is educed forward according to the random access channelconfiguration information and the preamble sequence format; the mannerfor determining the start position of the random access channel inmethod 2 is utilized for other uplink slots, that is, the start point ofthe uplink slot is considered as the start position of the random accesschannel.

Alternatively, the manner for determining the start position of therandom access channel in method 1 is utilized for the first M uplinkslots in the downlink-uplink transmission period; and the manner fordetermining the start position of the random access channel in method 2is utilized for the remaining uplink slots. Wherein the parameter M maybe configured and indicated in the System Information and RMSI by theBS, or be configured in a predetermined manner.

It should be noted that the present embodiment does not use the X2uplink symbols in the frame structure illustrated in FIG. 10 for therandom access channel configuration.

It may specify that uplink symbols in the special subframe are not forthe transmission of the random access preamble sequence.

With the method according to the present embodiment, a switching ofdownlink-uplink and inter-BS interferences in the TDD system may beprevented from interfering the random access channel, so that aperformance of the random access process can be enhanced in the TDDsystem.

Eighth Embodiment

All of the previous embodiments are for the random access channelconfiguration in the initial access bandwidth. The configurationsdescribed above may also be applied to other random access applicationscenes besides the initial random access, for example, a transmission ofschedule request, a random access process trigged by a downlink controlchannel, etc., but the random access channel may be configured in otherBandwidth Part (BWP) in order to reduce a terminal access delay, avoidfrequent switches among different BWPs and the like. The presentembodiment would discuss the configurations of the random access channelon other BWPs.

In the present embodiment, the BS configures the random access channelon the initial access BWP with the random access channel configurationinformation, etc. in RMSI, wherein the random access channelconfiguration is used to configure the resource in time domain of therandom access channel, and the resource in frequency domain isconfigured and indicated by an offset of a start Physical Resource Block(PRB) with respect to the initial access BWP. Random access channelconfiguration for other BWPs may be in manners as follows.

1. It is specified that the same random access channel configurationinformation is utilized for all BWPs, and is indicated and configured byhigher layer signaling or physical layer signaling commonly for cells orspecified for terminals. Wherein the random access configurationinformation, including the random access channel configuration and afrequency domain offset, may utilize the same configuration informationas the initial access BWP, and no additional signaling is required to beconfigured and indicated at this time; or, the random access channelconfiguration information as same as the initial access BWP anddifferent frequency domain offsets may be utilized, and the frequencydomain offsets are required to be configured to other BWPs at this time.Other BWPs may utilize the same frequency domain offset; may utilize thesame frequency domain offset as the initial access BWP and differentrandom access channel configuration information, and the random accesschannel configuration information is required to be configured to theother BWPs at this time. The other BWPs may utilize the same randomaccess channel configuration information; or the other BWPs may utilizedifferent random access channel configuration information and frequencydomain offsets from the initial access BWP, and the BS configures withthe higher layer signaling or physical downlink control channel.

2. The configurations of the random access channels on the other BWPsmay be performed by terminal-specified signaling. For the other BWPsexcept for the initial access BWP, the random access configurationinformation as same as that on the initial access BWP is utilized, andthe index or index group of the BWP available for the random access isindicated in the terminal-specified signaling. This signaling may be ahigher layer signaling, or may also be a physical layer signaling, suchas a downlink control information in a downlink control channel.

The terminal acquires the index or index group of the BWP available forthe random access via the higher layer signaling or physical layersignaling, and determines the time-frequency resources of the randomaccess channel in the BWP available for the random access according tothe random access configuration information transmitted in the RMSI.

Particularly, the resources in time domain of the random access channelmay be acquired via the random access channel configuration; and thefrequency domain offset of the random access channel may be understoodas an offset of the start PRB with respect to the BWP available for therandom access.

3. The configurations for the random access channels on other BWPs areperformed by the terminal-specified signaling. The BS configures theindex or index group of the BWPs available for the random access, andconfigures the frequency domain offsets of the random access channelsfor the BWPs available for the random access channels. The frequencydomain offsets may be uniform for all of the BWPs available for therandom access channels, that is, the same frequency domain offset isutilized; alternatively, different frequency domain offsets areconfigured for respective BWPs.

In a case of uniform frequency domain offset, a corresponding signalingis

{B ₁ , . . . ,B _(K) },f _(RA),

wherein {B₁, . . . , B_(K)} is the index group of the BWPs available forthe random access, f_(RA) is the frequency domain offset, namely thefrequency domain offset with respect to the BWP of the start PRB.

In a case of separately configured frequency domain offset, acorresponding signaling is:

{B ₁ , . . . ,B _(K) },{f _(RA1) , . . . ,f _(RAK)},

wherein {f_(RA1), . . . , f_(RAK)} is the frequency domain offsets forthe respective BWPs of the random access channels.

The random access channel configuration information for other BWPsutilizes the random access channel configuration information of theinitial access BWP.

4. The configurations of the random access channels on the other BWPsare performed by the terminal-specified signaling. The BS configures theindex or index group of the BWPs available for the random access, andconfigures the random access channel configurations for the BWPsavailable for the random access channels. The other BWPs available forthe random access utilize the frequency domain offset configuration assame as the initial access BWP.

5. The configurations of the random access channels on the other BWPsare performed by the terminal-specified signaling. The BS configures theindex or index group of the BWPs available for the random access, andconfigures the random access channel configurations and the frequencydomain offsets for the BWPs available for the random access channels.

If the terminal has been configured to transmit the data through the BWPexcept for the initial access BWP by the BS and needs to the randomaccess, the time-frequency resources of the random access channel andthe preamble sequences are selected according to the random accessconfiguration information on the BWP, and the preamble sequencesselected or configured by the BS are transmitted in the random accesschannel on the BWP.

If the configured BWP has no random access configuration information,the terminal needs to initiate a BWP handover process so as to handoverto an initial access bandwidth or a BWP in the random access channel, toperform the random access process.

If the random access process is triggered by the BS (for example, arandom access process triggered by the downlink control channel) and theBWP currently configured for the terminal has no random access channel,the BS schedules the terminal to the initial access BWP or the BWP inthe random access channel at first, and next triggers the random accessprocess.

FIG. 15 is an exemplary view illustrating a random access preamblesequence detection method at the base station side according to thepresent disclosure.

According to FIG. 15 , the present disclosure provides a random accessdetection method as follows. At step S1010, transmitting synchronizationsignal blocks including a primary synchronization signal, a secondarysynchronization signal and a broadcast channel. At step S1020, detectingrespective random access occasions in a random access channel. At stepS1030, determining downlink transmitting beams for transmitting a randomaccess response according to time frequency resources of the randomaccess occasions and/or the detected random access preamble sequences,if the transmission of the preamble sequences is detected. At stepS1040, transmitting the random access response by the downlinktransmitting beams determined at step S1030. FIG. 15 illustrates anaction flowchart at the base station side. Wherein the detected preamblesequences detected at step S1030 are transmitted on the time frequencyresources of the random access occasions determined by the terminalbased on the method described in the above First to Third embodiments.

FIG. 16 illustrates a random access channel time frequency resourceacquiring and determination apparatus included in the terminal accordingto the present disclosure.

The present disclosure provides an apparatus for acquiring anddetermining time frequency resources of a random access channel, asillustrated in FIG. 16 . The apparatus comprises: a downlink measurementmodule 1110 configured to determine synchronization signal blocks basedon a downlink measure result; a configuration information acquisitionmodule 1120 configured to read random access channel configurationinformation from the synchronization signal blocks; a random accessoccasion time frequency resource determination module 1130 configured todetermine a time frequency resource position of the random accessoccasion according to the random access channel configuration andassociation information; a preamble sequence transmitting module 1140configured to transmit the preamble sequence on the random accessoccasion. Wherein the random access occasion time frequency resourcedetermination module 1130 determines the time frequency resourceposition of the random access occasion based on the method described inthe above First to Third embodiments.

FIG. 17 illustrates a preamble sequence detection apparatus included inthe base station according to the present disclosure. The presentdisclosure provides a preamble sequence detection apparatus, asillustrated in FIG. 17 , which comprises: a synchronization signal blocktransmitting module 1210 configured to transmit the synchronizationsignal blocks; a preamble sequence detection module 1220 configured todetect the preamble sequences on the respective random access occasionsof the random access channel; a downlink beam determination module 1230configured to determine downlink beams according to the time frequencyresources of the random access occasions and the preamble sequences; arandom access response transmitting module 1240 configured to transmit arandom access response using the determined downlink beams. Wherein thepreamble sequences detected in the preamble sequence detection module1220 are transmitted on the time frequency resources of the randomaccess occasion determined based on the method described in the aboveFirst to Third embodiments.

The present disclosure provides an acquisition and determination mannerof time-frequency resource of the random access channel in a multi-beamoperation system. With the methods provided by the present disclosure,the system can configure the time-frequency resources of the randomaccess occasions corresponding to the different beams in a smallersignaling overhead. Further, the terminal can acquire the information onthe random access occasion more quickly, so that the entire performanceand operation efficiency of the system are improved.

In order to facilitate the understanding of the exemplary embodiments,some exemplary embodiments of the acquisition and determination mannerof time-frequency resource of the random access channel in themulti-beam operation system according to the present disclosure havebeen described and illustrated in drawings. However, the above are onlyexemplary embodiments of the disclosed solution, but the scope soughtfor protection is not limited thereto. Instead, any or all modificationsor replacements as would be obvious to those skilled in the art areintended to be included within the scope of the present invention.Therefore, the scope of the present invention is defined in the appendedclaims.

What is claimed is:
 1. A method performed by a terminal in a wirelesscommunication system, the method comprising: receiving, from a basestation, a configuration including a random access channel (RACH)configuration index; identifying a RACH occasion based on theconfiguration; and transmitting, to the base station, a random accesspreamble based on the RACH occasion in a system frame, wherein the RACHconfiguration index indicating a RACH period, and wherein an index ofthe system frame is determined based on a modulo function with the RACHperiod as an input.
 2. The method of claim 1, wherein the index of thesystem frame satisfies mod(Nf, Nperiod)=k, and wherein the Nf indicatesthe index of the system frame, and wherein the Nperiod*10 ms indicatesthe RACH period.
 3. The method of claim 1, wherein the RACH period isset as one of 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.
 4. The method ofclaim 1, wherein the RACH configuration index indicates a preambleformat and a starting symbol.
 5. A method performed by a base station ina wireless communication system, the method comprising: transmitting, toa terminal, a configuration including a random access channel (RACH)configuration index; and receiving, from the terminal, a random accesspreamble based on a RACH occasion in a system frame, the RACH occasionbeing identified based on the configuration, wherein the RACHconfiguration index indicating a RACH period, and wherein an index ofthe system frame is determined based on a modulo function with the RACHperiod as an input.
 6. The method of claim 5, wherein the index of thesystem frame satisfies mod(Nf, Nperiod)=k, and wherein the Nf indicatesthe index of the system frame, and wherein the Nperiod*10 ms indicatesthe RACH period.
 7. The method of claim 5, wherein the RACH period isset as one of 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.
 8. The method ofclaim 5, wherein the RACH configuration index indicates a preambleformat and a starting symbol.
 9. A terminal in a wireless communicationsystem, the terminal comprising: a transceiver; and a controller coupledwith the transceiver and configured to: receive, from a base station, aconfiguration including a random access channel (RACH) configurationindex, identify a RACH occasion based on the configuration, andtransmit, to the base station, a random access preamble based on theRACH occasion in a system frame, wherein the RACH configuration indexindicating a RACH period, and wherein an index of the system frame isdetermined based on a modulo function with the RACH period as an input.10. The terminal of claim 9, wherein the index of the system framesatisfies mod(Nf, Nperiod)=k, and wherein the Nf indicates the index ofthe system frame, and wherein the Nperiod*10 ms indicates the RACHperiod.
 11. The terminal of claim 9, wherein the RACH period is set asone of 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.
 12. The terminal of claim9, wherein the RACH configuration index indicates a preamble format anda starting symbol.
 13. A base station in a wireless communicationsystem, the base station comprising: a transceiver; and a controllercoupled with the transceiver and configured to: transmit, to a terminal,a configuration including a random access channel (RACH) configurationindex, and receive, from the terminal, a random access preamble based ona RACH occasion in a system frame, the RACH occasion being identifiedbased on the configuration, wherein the RACH configuration indexindicating a RACH period, and wherein an index of the system frame isdetermined based on a modulo function with the RACH period as an input.14. The base station of claim 13, wherein the index of the system framesatisfies mod(Nf, Nperiod)=k, and wherein the Nf indicates the index ofthe system frame, and wherein the Nperiod*10 ms indicates the RACHperiod.
 15. The base station of claim 13, wherein the RACH period is setas one of 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms.
 16. The base stationof claim 13, wherein the RACH configuration index indicates a preambleformat and a starting symbol.